Hi, I'm Vapora Dark, a veteran player that's been playing since season 1. During that time I've hit Master tier as a mid lane main in season 5, as an ADC main in season 7, again as a jungle main in season 8, and once more in season 9 playing a mix of all those roles, but mainly ADC including Kai'Sa. I can play every role to a very high level and have a very good understanding of the general aspects of the game on top of that.
I've been writing guides on MOBAFire since 2011, among which my achievements include winning the MOBAFire guide contest multiple times, achieving the highest score on the site multiple times with multiple guides, achieving the most comments on a single guide of all time by a very large amount which hasn't come even close to being surpassed in the 3 years that it's been archived, and having the most collective guide views on the site by a very hefty amount. I've also written some champion guides for Riot Games on the Lolesports site.
Kai'Sa's been one of my top 2 favourite ADCs since release as well as one of my best ADCs when I'm looking to win games.
Kai'Sa can be also played in the jungle as well as in funnel duos with a premade, but this guide will be focused on her most popular role, bot lane.
I hope you enjoy reading the guide as much as I enjoyed writing it, and that by the end you feel my guide was worth the privilege of your time.
In this chapter I'm going to be gathering a compilation of Kai'Sa footage ranging from full gameplays from myself and more skilled players to help you learn the champion even better if you're willing to put in the time to watch some extra content on top of the actual guide itself, as well as give you an idea of what the champion can achieve in the hands of a good player. Make sure to subscribe to keep up with all educational and other content that I put out.
Triumph: This can be a life saver in close fights, and the 20g per takedown actually adds up to quite a bit in bloody games.
Legend: Bloodline: With the change to make bloodline give you 12% lifesteal, the healing you get is more useful than the attack speed in every situation. Even in your AP games, your first 2 items are physical damage and hybrid meaning you still make decent use of the healing at least early.
Coup De Grace
Coup de Grace: This is the best rune in its tree for almost every champion that wants to go into Precision since it's the one that simply does the most damage in your average game.
Magical Footwear: Currently, all marksmen should go inspiration. The power of getting a free pair of 300g boots with extra movement speed is far too good to pass up. Whilst you don't get it for 12 minutes, takedowns lower this time. Plus you don't need boots early in this role pretty much ever anymore.
Biscuit Delivery: As the average game time has gotten shorter and shorter, lane sustain has become very powerful. As most carries buy no sustain for the early game, the missing health/mana regeneration the biscuits offer are second to none. The utility of these 2 runes is far too strong to pass up and as they'll be active in the game from the very start and have permanent effects they will never not be useful.
Offense: 10% Attack Speed
Flex: 9 Adaptive Force
Defense: 6 Armour
Flash and Heal has been the standard ADC summoner spell combination since possibly mid-season 3. In fact, Flash has been the standard summoner spell to take on almost every single champion since forever. It's always been indisputably the best summoner spell in the game, so there's nothing you can replace it with.
Heal on the other hand, replaced Barrier when it got buffed in season 3 to give movement speed on the cast, which is the reason it's been standard over Barrier ever since, despite being affected by Ignite's Grievous Wounds. Aside from the small movement speed boost, which can be used both offensively and defensively, another reason why it's stronger than Barrier is it affects an ally, which is perfect for bot lane where you're laning with a support.
The reason you want a defensive summoner on ADC is that you have a lot of DPS, so the longer you can survive, the more damage you'll put out, usually out-damaging what you'd get from Ignite. And if it can go as far as to save your life, then that's even better, as ADC's are very important to have alive for both providing DPS and taking down objectives.
Passive: Second Skin
Second Skin: The on-hit from this passive makes attack speed an amazing stat on Kai'Sa, and the execute makes her most effective against low HP enemies.
Additionally, she can evolve her spells based on her stats. Many people are too obsessed with focusing their build on evolving all 3 spells, but truth is evolving Void Seeker isn't very useful on AD Kai'Sa and is more oriented towards AP Kai'Sa, so even though we build some AP through Guinsoo's Rageblade (only because it's a good item for on-hit users), it's not worth building any more AP just to evolve Void Seeker.
Icathian Rain: This spell gives you some waveclear, not great waveclear but it's better than nothing. Where it really shines is during 1v1s away from minions where the missiles all concentrate onto one target, especially once you evolve it.
W: Void Seeker
Void Seeker: This isn't too useful for harassing, but in fights you can use it in between auto-attacks to add a little bit of damage.
Its most important use however is to enable you to engage on someone with Killer Instinct. It has an enormous range and so does Killer Instinct, making the synergy between them very strong.
Supercharge: This ability is nice for giving Kai'Sa some mobility, helping her kite, escape and dodge abilities whenever necessary. Especially once you evolve it it becomes very good since people won't be able to focus you while you're charging as you'll be invisible.
It's also obviously great as an attack speed steroid, as +60% AS is a huge amount. Make sure to only use it either when you know you can commit to a fight, or when you need the mobility/invisibility from charging it.
R: Killer Instinct
Killer Instinct: This ult was intended to be a pure aggression ult, but it can also be used defensively by ulting a target that gets into melee range of you and just dashing a short distance away from them. It also gives you a shield to protect you from damage if necessary.
One thing you need to remember is that this doesn't do any damage at all, it's purely mobility/engage and a shield. It's only useful in duels if you need to reposition or if you need the shield.
Doran's Blade: Doran's Blade is the best starting item for all-ins, thanks to the HP it provides on top of the AD. Doran's Shield is also an alternative that's viable in lanes where you're likely to be harassed a lot, such as when facing a high pressure support like Zyra.
Manamune: In a bizarre turn of events, Manamune has become the best item to rush on Kai'Sa and lets her go into with an AP or AD build after her third item instead of choosing earlier. The amount of attack damage you get from this item is enough to, in combination with a Pickaxe or Guinsoo's Rageblade, evolve your Icathian Rain. That combined with being dirt cheap makes it a powerful item. To top it all off though is that once you hit the breakpoint and fill the tear up you get Muramana. As Kai'Sa doesn't spam her abilities she rarely uses her mana, which is now turned into on-hit damage which also works with Guinsoo's Rageblade.
Berserker's Greaves: You'll want to build these after your first item for the extra mobility, or even sooner if you feel you need it and once you have them both. You'll need these boots always as you'll want to upgrade Supercharge.
Runaan's Hurricane: At the point you'll either choose to go AD or AP based on what your team needs. As your third item you'll want to start stacking more critical strike chance. Runaan's Hurricane is the best option for Kai'Sa as it lets her spread Second Skin to multiple targets at once.
Infinity Edge: Continuing on with the AD Kai'Sa build, your fourth item is an Infinity Edge to give you a comfortable 50% critical strike chance, a lot of attack damage and an increase to your multiplier.
Guardian Angel: This is a super strong item on ADCs because it gives damage and so much survivability for such a cheap cost. You'll basically want to build this as one of your full build items in almost every game.
Nashor's Tooth: Now we'll talk about the ability power version of Kai'Sa. This will be your third item after finishing your Guinsoo's Rageblade. Gaining a large amount of CDR AP and Attack Speed makes this perfect for her. The on-hit magic damage also has massive synergy with Second Skin.
Zhonya's Hourglass: One of the biggest weaknesses any squishy champion with low range is being bursted quickly. This is usually a massive weakness for the class that is exploited by other classes to make the game like rock/paper/scissors. Kai'Sa doesn't play by those rules and can easily buy Zhonya's Hourglass to become next to unkillable in conjunction with Killer Instinct.
Rabadon's Deathcap: As with any ability power base champion, the single biggest power spike you can buy is a Rabadon's Deathcap. Gaining a huge amount of ability will make your basic attacks deal a very large amount of magical damage on hit as well as burst for a massive amount with Void Seeker and the execute from Second Skin.
Banshee's Veil: Heavy magic damage threats are everywhere, with champions like LeBlanc, Akali, Evelynn and even supports like Brand all being common picks. Banshee's Veil not only offers a large amount of ability power, some cooldown reduction and a high magic resistance stat is has the unique passive of a temporary spellshield that blocks a single ability every 40 seconds. Perfect for preventing assassination combos and deadly pick abilities as well (such as Rocket Grab from a Blitzcrank.) In combination with Killer Instinct and Zhonya's Hourglass you can become one of the more tanky champions on your team resistance wise whilst still putting out a huge amount of damage.
A quick thing to mention about choosing between which build to go. You'll by default want to go the critical strike build as it's cheaper and more forgiving. It also scales faster and the usual physical damage DPS champion is the role Kai'Sa takes on the team. However the ability power version of Kai'Sa offers the ability to be a magic damage carry if your team is lacking magical damage, or if the enemy team all deal high damage and have few tanks. The downside is that it's a more expensive build and relies more heavily on being able to constantly land Void Seeker for good poke. It also flat out deals less DPS in an auto attack based fight. Both are equally as viable and it's up to you to decide based on the teamcomps/how the game is going to choose which to go.
Bot Lane Matchups
Bot lane matchups are a very complex subject. On solo lanes or jungle matchups it's easy to say that one champion beats or counters another, or that a matchup is even and can be considered a skill matchup.
Bot lane is unique in being a 2v2 lane and to top it off the supports are often even more impactful than the ADCs, so you have to factor the support into the matchup just as much if not more than the ADC, and also the strengths and weaknesses of each support relative to the strength and weaknesses of their partner as well as their two opponents. There's such a ridiculous amount of possible combinations you can run into (minimum 560 counting only common picks) that it's simply impossible to explain the dynamics of how every single matchup should play out, nor can I rate the difficulty of each ADC or support matchup individually because depending on the supports, your pick can either win lane against every ADC/support or lose lane against every ADC/support.
So I'm going to dedicate this chapter to giving a small rundown of what you need to know about laning against each champion, both the ADCs and the supports, and a rating of what their general strength in lane is, which is not necessarily a rating of how difficult your lane will be if you're playing against them in solo queue as it varies depending on who their lane partner is and also who their opponents are, for example champions like Nami can be either big lane bullies against champions like Janna or just passive laners who are otherwise free kills for champions like Thresh; but both matchups also massively depend on their partner and the opponent's partner.
Deep understanding of each champion on an individual level coupled with first-hand experience in witnessing how many different duos perform with each other will lead to a greater understanding of how any given bot lane matchup is likely to go, and with the following brief analyses of each bot lane champion I hope to give you as much of a head start in this area as I reasonably can.
Ashe has very easy to land long range AoE poke, but it's not particularly strong and on a very high cooldown, resulting in low waveclear, weak trades and weak all-ins.
However she's one of the highest auto-attack range ADCs and can easily poke with her auto-attacks, meaning if your bot lane duo is one that can't pressure her and scare her off of trading, she can end up bullying you pretty hard in said matchups despite being an overall weak laning champion.
For a long time regarded as the queen of laning phase, Caitlyn's had a lot of power taken out of her laning phase and given to her mid-late game, and playerbase perception hasn't yet to catch up with the times. She's still a massive lane bully and will win almost any lane that comes down to trading and waveclear, but she's very weak in all-ins and will get crushed in fights by any bot lane that can engage on her.
Because of how extreme her strengths and weaknesses are her threat level really varies between high to low, so I chose medium as a compromise, but beware of how utterly dominant she can be in lane if you don't have a good matchup against her.
Draven is the absolute king of laning phase in today's League, far beyond what Caitlyn ever was at her peak. He is simultaneously the strongest ADC in short trades, long trades, and second best in all-ins. Never has a champion quote ever been more true than "Draven does it all". However, even Draven is not quite without weakness. He's short-ranged and has no escapes so he's very vulnerable to being engaged on. Unfortunately he's so strong in all-ins that if you engage on him there's a good chance he'll just turn it into a double kill, but as with all bot laners, a duo with strong enough all-ins while Draven has a support poorly suited to deal with them is all it takes to overcome the king of laning phase.
Additionally, because of his short range and poor waveclear he can be easily handled by champions who can pressure him from outside his range like Caitlyn on the ADCs' side or Zyra on the supports' side, on the condition that he's not paired with a support that has the ability to easily engage on and lock down these long range champions for Draven to reach and kill, such as what Thresh or Nautilus would bring to the table.
Ezreal is a champion that is primarily picked for safety, he is very hard to kill in lane and his long range low cooldown Mystic Shot allows him to easily keep up in CS from a range in situations where other ADCs wouldn't be able to farm.
In exchange for being so hard to snowball against, he's also made to lack the tools to snowball himself. He has weak waveclear, unnoteworthy all-in power, and would be decent at trading if not for the fact that he can't poke through minions. He will never create a winning matchup solely on his own merits.
However, bot lane being as complicated as it is, if his duo as a whole is one that is either stronger in all-ins or stronger at trading and he is able to pressure the lane rather than play defensively, Mystic Shot becomes an excellent poke tool and he can exert a lot of pressure with his range, similarly to Ashe but stronger.
Jhin's fourth shot hits like a truck, giving him very strong zoning potential and damage when trading with it, which combined with his decent waveclear makes him a strong lane bully in most matchups.
He's okay in all-ins when following up his support's engage to finish someone off, but his damage is not great in extended fights and he is himself highly vulnerable to being engaged on and burst down.
Jinx comes online for teamfights very early into the game but has a miserable laning phase. She's weak at trading, weak in all-ins, has inefficient waveclear, suffers from Ezreal's problem of having decent poke that's impossible to actually use unless you're already winning lane, and is also highly vulnerable to being engaged on.
On the bright side, when the matchup actually does allow her to have pressure in lane Zap! allows for some very high range, very high damage poke, and she has very high auto-attack range to pressure with as well as decent CC and burst to follow up engages with, so should you find yourself on the losing end of a matchup against her don't expect her overall weak laning phase to make toughing through the matchup a breeze.
Kai'Sa has a lot of winning matchups while only having a few losing ones, but she doesn't excell at any particular area. She's decent in trades, has decent waveclear and decent all-ins which makes her a versatile champion fitting well into most matchups and supports, but she generally won't crush you in any individual aspect and can be beaten by duos that strongly outshine her any areas, and is especially vulnerable to ADCs that can best all-in her. Her mobility is decent enough though that she's not overly vulnerable to engages compared to the more immobile ADCs.
A Challenger level Kalista wins almost all lanes, but the average Kalistas you'll encounter in your games won't be quite so impressive, generally winning against low threat ADCs, going even against medium threat ADCs and losing to high threat ADCs.
She's a lane bully that can pressure opponents quite well with her high mobility, low CD trading and strong poke to develop healthy CS leads, but she lacks upfront damage in fights, loses DPS when slowed and is generally quite easy to kill once locked down. However, when in a winning matchup she can be very oppressive due to her high mobility and ability to help her support engage.
Kog'Maw is best known for being a mid-late game hypercarry and respectively his laning phase is appropriately weak to compensate. He can't push very well early on, has very weak trading in lane, very weak poke until level 6 when it becomes okay, very poor followup to engages, and is himself highly vulnerable to them.
When actually in a winning matchup he won't have a hard time exerting pressure between his massive auto-attack range during Bio-Arcane Barrage and his long range poke with Living Artillery, but he doesn't bring much kill potential to the lane. When in a bad matchup he won't have a problem farming safely while avoiding trades but can be easily divable by a strong enough all-in duo.
A traditional lane bully, Lucian sacrifices mid-lategame power in exchange for putting it all into his laning phase. Lucian has great waveclear, decent poke, great trades, is great in all-ins, has great followup to engages, and has great mobility to keep him safe from engages. He's a little worse than draven at most aspects besides waveclear but his extra mobility makes him safer and also better at abusing his leads when he has them, especially as he typically rushes Blade of the Ruined King which also gives him a solid slow to force kills with.
Lucian will typically lose lane into matchups that outrange him when his lane can't easily force engages, or can lose to duos with stronger all-ins.
Miss Fortune is a champion who can be a massive lane bully into many matchups given the huge range and damage of her Double Up, but she suffers from being too easy to kill when engaged on. Against matchups that can't all-in her though, whether in a poke-focused lane or paired with an engage support she can pack a massive punch through Double Up poke and Bullet Time damage in fights.
Sivir is probably the most underrated laning phase ADC there is. She has the best waveclear of any ADC at later levels and still really good waveclear earlier on, great poke, decent trades, is okay in all-ins, is relatively safe from being engaged upon by basically any support that isn't Alistar, and is really good at helping her support engage with On The Hunt. Her short range however means that she's easy to poke and is vulnerable to engages that don't rely on CC that she can spell shield.
Tristana has bad early waveclear, really bad poke and really bad trades, but her strength in all-ins in matchups where she can fully stack her Explosive Charge is absolutely unmatched, and her massive dash range with Rocket Jump makes it easy for her to force all-ins at the drop of a dime. With all her power focused onto this one single strength, it makes for a highly explosive and action packed laning phase, where at any moment she can jump on you and one-shot you.
She has a hard time into matchups where she can't win all-ins, usually either as a result of CC leaving her unable to stack her Explosive Charge in time, or Exhaust nullifying her burst when she does. Since all-ins are her one strength, in matchups where she can't force them she ends up being really useless and falls pretty far behind. However, her amazing mobility also makes her really safe and hard to kill even against bot lanes with great engage.
Twitch may be marked as a low threat, but that doesn't mean you can let your guard down against him. Twitch has bad waveclear, bad poke, is bad at short trades and is highly vulnerable to engage, making him an extremely weak champion in lane overall. However he's okay in extended trades where he has time to stack up Contaminate, and Ambush makes him the best ADC at forcing fights on his own terms when it favours him.
Despite being extremely weak in all-ins and trades and on average being down in CS into every single matchup as a result of it, he still averages being up on kills into every ADC except Tristana. It isn't enough to make his laning phase good given that on average he still falls behind in gold to every ADC except Vayne and Kog'Maw, but it goes to show that while his laning phase in a vacuum may be terrible, you still need to be very careful and aware to make sure that you don't end up giving him free kills in situations where he can sneakily engage on you when it favours him.
Varus has decent waveclear, poke and trading, and his ult is an amazing engage tool which coupled with his bursty kit makes him decent in all-ins too. However as a jack of all trades that makes him easy to beat in a matchup that's much better than him at any given aspect.
Being a late-game hypercarry, Vayne has bad waveclear, bad poke, bad trades and poor all-ins. On the other hand she's relatively safe, and she's great at following up engages or engaging herself when she's in a winning matchup. But she pretty much loses any lane so long as the support difference isn't enough to compensate for it.
Xayah has great waveclear, decent poke, good trades and great all-ins especially when paired with a CC support while also being safe from engages and having great followup to engages by bringing CC of her own. All around a very solid laner, but is quite short ranged and can be easily handled by matchups that can keep her at a distance or beat her in all-ins.
Alistar is a rather weak laning support overall given his vulnerability to being poked, the ease with which his WQ combo can be interrupted by many supports with displacements, and the fact that any CC or mobility spell can prevent him from stunning his target with Trample.
However, after level 6 with Unbreakable Will active he's also the tankiest support in the game, and with all 3 of his non-ultimate spells being CCs and mostly displacements it makes him very hard to ignore in skirmishes.
It also makes him great at setting up plays, so if he is in a winning matchup it makes it very easy for him to dive 2v2 or with the jungler's help, given that he can tank up the tower for long periods of time while CCing the targets to allow his team mates to safely finish them off.
With Cosmic Binding and Traveler's Call, Bard has probably the strongest level 1 of any support which is something you always have to watch out for when playing against him, but in further levels he gains very lackluster abilities and falls off to rather middle of the pack in terms of laning strength, able to beat up the weaker laning supports but also getting beat up by the stronger ones.
He's very good at low-range trading and has a reasonable amount of healing to sustain his ADC and himself despite not quite falling into the healer category of supports, and can set up good engages with Tempered Fate to allow his team to catch up to the caught enemies and kill them, and also allow himself to get into position to stun them either against a wall or each other with Cosmic Binding.
He himself though is quite vulnerable to engages especially when not near a wall he can Magical Journey to for an escape, and since he only has one damage spell and auto-attacks/passive to trade with can also be quite vulnerable to poke from stronger trading supports.
Blitzcrank is probably the most hit or miss champion in League of legends, both literally and figuratively. If he hits his Rocket Grab it will likely turn into a kill, but if it misses he proceeds to have absolutely no lane presence over the next ~18 seconds until it comes back off cooldown and his ADC may as well be laning 1v2.
So obviously it goes without saying that his all-ins have the potential to be great if he's the one forcing them by landing a good hook, but when missed or if used on a melee range target he's rather weak since he doesn't bring much to the table other than forcing a target to become horribly mispositioned and briefly CC'ing them in that spot.
He's generally weak into strong laning supports that can control the lane and make him scared to walk up to hook for fear of taking too much damage or getting caught himself, but can be quite successful into some of the weaker laning supports, especially into enchanters. Though the opponent's general strength in lane is still the overall biggest factor, Blitzcrank is more so happy to face enchanters than other supports, and likewise shines into immobile ADCs who have no easy way of dodging the hook and have to play defensively and far back to avoid putting themselves into a position where they can get hooked.
Brand's combination of strong long range poke, one hard CC and immense burst make him one of the strongest laning supports in the game, alongside most mage supports.
Given the range of his poke along with its strength it's very hard to beat Brand through trades and therefore makes strong all-in lanes with good engage the best chance at beating him in lane, but pre-6 he has the proper tools to keep his opponents too low to be able to risk engaging and after 6 with Pyroclasm he can potentially blow up two targets at once in fights, so all in all there's just no getting around the fact that Brand is just not a champion that ever expects to lose lane, except against other mage supports for whom you can also say the same thing.
Braum has great peeling and defensive properties for keeping his ADC safe in teamfights, but this translates very poorly into laning phase strength where he's just a low-CC melee support with no damage, no way to fight back against poke, and not particularly safe from getting engaged on, so rather abusable in pretty much any matchup.
Fortunately he's very tanky to make up for it so not particularly easy to kill, and Unbreakable can often save his ADC's life in fights too, but overall he's the weakest laning support in the game.
Fiddlesticks has two equally viable spells he can max based on his needs or desires, either Reap to focus on poke or Terrify to weaken enemy trades/all-ins, either way though he has a good time in most trade/poke focused matchups.
Engage is the best way to deal with him but he has the option of taking Aftershock to instantly proc with Terrify if he ever gets engaged on so he gets very high resistances on top of CCing one of his attackers for a high duration, so unless he can be CC chained or caught off guard with cooldowns he's not particularly vulnerable.
Additionally at level 6 he becomes very strong in all-ins where he has the opportunity to jump in with Crowstorm and can find creative ways to force a fight by surprise and catch people out, making him a threat you always have to be particularly cautious of.
Janna can either max Zephyr to prioritise trading and controlling the lane, or Eye Of The Storm to prioritize keeping herself and her ADC safe while still offering some extra damage through the AD and having reasonable poke in her unmaxed Zephyr.
She's weak in all-ins but is also great at protecting herself and her ADC from all-ins in many matchups, making her an overall decent support while still being slightly on the weaker side, though vulnerable to supports with longer range poke and supports who can engage without being affected by her Howling Gale.
Mantra-empowered Inner Flame is probably the strongest poke spell you'll find on bot lane which does massive damage and is very easy to hit, but Mantra has a long cooldown and Inner Flame on its own is rather short ranged while still doing decent damage and making it easy to shove and control waves.
Being a sort of enchanter/mage hybrid she doesn't really shine at either aspect, but her magelike qualities make her a rather good laning champion despite not being quite on the same level as other pure mage supports, and her enchanter qualities make her decent at protecting and buffing her allies, despite not being quite as good at it as pure enchanters.
The greatest thing that Leona offers is easy engage onto vulnerable short range targets, since her Zenith Blade travels through minions which is a feature most engage champions lack on their engage tools.
However it's also quite short ranged which is a big disadvantage over them and her all-ins are not as strong as other engage champions, so while she has an easy time forcing fights to extend her lead in good matchups, she doesn't necessarily have a great deal of good matchups, so is best paired with a strong laning ADC and works best when picked against weak laners.
Lulu has the ability to massively buff her ADC's damage mid-late game as well as offering great anti-burst protection and works best paired with hypercarries, so given her scaling it's not surprising that her laning phase isn't that great. She does pack a lot of damage however, so she can definitely act as a bit of a lane bully in winning matchups, but she needs to get in close range to use it and can easily get blown up in many matchups.
Whether maxing Lucent Singularity to focus on poke or Prismatic Barrier to shield massive amounts of damage for her ADC, Lux brings a lot of damage to the lane either way, and brings both pressure and kill potential, using her long range poke to wear enemies down coupled with her long range snare enabling her to burst down low enemy laners.
However to get the most damage out of her kit she has to get in auto-attack range to proc Illumination, without which she misses out on a lot of damage especially if she maxes Prismatic Barrier, which opens up room for enemy laners to try and punish her either by trading back or engaging on her.
Black Shield makes Morgana a hard counter to most of the CC reliant supports, but the rest of her kit is also strong enough that she generally performs quite well into enchanters too. With Dark Binding and Tormented Shadow she can inflict a great deal of poke damage, and with Dark Binding scaling up to 3 seconds of CC she has very high pick potential, especially after level 6 when she can follow it up with Soul Shackles for a longer lock-down. In general Soul Shackles can make her a large threat in all-ins since she can Black Shield herself to make sure she can't be CC'd so she can complete the channel, and if she uses it before Dark Binding she can guarantee a very high lockdown period onto a target she stuns.
The only supports that can reliably beat her are lane dominant mage supports, but she isn't an awful pick into these either since her Black Shield at worst can act as a regular shield and can also be used to counter any CC these champions commonly have.
Nami brings a perfect balance of poke and healing as she improves both when ranking up her Ebb and Flow, and can frequently both poke and heal her or her ADC with one cast, making it easy to keep her and her ADC topped up and healthy while also applying pressure in the matchup.
Her all-ins however are generally not all that great, hinging massively on her ability to land her slow moving Aqua Prison. When she does hit it she's rewarded greatly with a decent CC duration which can turn around many fights. But when she doesn't her contribution to fights isn't great and even with her heal she's still quite squishy and vulnerable. She scales decently into mid-game though and is a wonderful asset for helping her ADC minimize their losses in lane while also doing a great job of bullying weaker matchups.
Additionally the fact that she does have options to force and win all-ins through her CC is something that gives her an edge in many matchups that other enchanters don't have.
Nautilus has gone through long periods of weakness in the support role, but currently at the time of writing this he is probably the strongest all-in support, bringing a heavy mix of high tankiness, decent damage and long range, very easy to land engage.
However he has no poke and can't engage through minions, so in matchups where he has no prio and can be punished for walking up to fish for hooks he won't be able to contribute much and is vulnerable to poke. When in winning matchups though his ease at engaging makes him very scary to face and can generate very large gold leads.
Pyke is currently the strongest support in lane, bringing the same playmaking utility you'd get from other engage/hook supports while also being highly mobile, rather tanky overall in extended scenarios where he can make ample use of Gift of the Drowned Ones, and also bringing a lot of damage into the matchup given his position as the only AD assassin support in the game.
He doesn't quite have the damage to one-shot a carry unless extremely fed, but coupled with his ADC's damage it makes it rather easy to bring a target below the execution threshold for Death from Below, making him great at snowballing especially given the fact that any targets executed by Death from Below give full kill gold to both Pyke and the ADC, causing winning matchups to generate more gold for the duo as a whole than they would for any other duo.
His high mobility and sustain also make it extremely hard to punish him except if he can be CC locked and burst down, making it hard to generate leads from him when he fails at making a play, while not being as forgiving for the enemy bot lane when he succeeds.
Being a scaling support, Rakan's laning phase is rather weak. His engage is hard to land, doesn't do much damage and he isn't particularly tanky to actually win the fights he engages. He has some poke but it doesn't do much damage, and some sustain but it's not on demand and isn't that strong. Sort of a jack of all trades that's weak enough in all aspects that he'll be outshined by most supports in lane.
At level 6 his engages become a little stronger as he can more consistently land Grand Entrance and also gets to charm one other target on top of that, but still isn't great engage compared to other engage supports. He does have special synergy with Xayah's Deadly Plumage in lane that makes his all-ins a lot stronger than they are with any other ADC, but still overall on the weaker side of engage supports.
Sona eventually ramps up to being one of the strongest lategame champions in the game even compared to non-supports, so naturally her laning phase suffers to compensate. First and foremost she's the second squishiest champion in the game besides Yuumi but doesn't get to go untargetable to make up for it, making her the most easily killable support to play in laning phase.
However she does bring decent poke and some healing and shielding for both herself and her ADC, causing her to have an easy time into enchanters and other weak laners who can't punish her in all-ins and allow her to scale and keep herself and her ADC topped up with sustain. However her aforementioned squishiness makes her very weak into stronger laners with either high damage or good engage who can punish her lack of defensive stats.
Soraka is the queen of healing in League of Legends, providing unparalleled levels of healing through Astral Infusion alone while also having a large global AoE heal in Wish to boot. Unfortunately this healing comes at the cost of her own HP and her own self-sustain is quite low and dependant on harassing enemies with Starcall, leaving a lot of room to punish her.
When in winnable matchups she has the option of maxing or putting some early points into Starcall in order to have higher poke in lane, but it's still quite short ranged and doesn't do all that much damage, leaving her still quite an underwhelming laner.
Kench doesn't have a great time into the majority of the support roster, but he actually does quite well into most melee supports. As these supports are mostly engage focused Devour is an invaluable tool for keeping his ADC safe, but additionally Tahm Kench has a ton of damage when he can Devour an enemy champion, but has a hard time stacking it against ranged champions.
Against melees on the other hand, this isn't a problem and he's much more capable of utilizing the full extent of his kit, and Thick Skin makes him incredibly tanky to the point where he isn't scared of letting himself be engaged on. So with this in mind he can certainly be quite strong in lane, but when looking at his performance on bot lane as a whole and not just against the champions he counters, his laning phase suffers quite a bit from his incapability of dealing with champions that outrange him.
Taric is the only melee pure enchanter in the game, every one of his spells except Dazzle being defensive to protect his allies, which makes him great at protecting, but very bad at fighting enemy champions considering he lacks the range that other already weak laning enchanters would have to their advantage.
He doesn't fair as badly into melee matchups since, similarly to Tahm Kench, he gets a lot of damage from his passive which he can't easily apply to ranged champions but can easily use on melees. However while this makes many melee matchups more bearable than ranged matchups, he still tends to not do very well into most of them.
Thresh combines the engage and pick potential of a melee champion with the trading pressure of a ranged champion. With Flay's passive combined with its active, Thresh packs a lot of damage in just one spell rank, and will often put a few early points into it to maximize his early damage. In winning matchups he can easily walk up to Flay an enemy towards him even through minions knowing he can win the trade. Flay is also great defensively and can block many champions' engage tools.
Additionally, the aptly named Death Sentence often spells disaster for targets caught by it as it stuns and pulls the victim closer to Thresh and his ally over 1.5 seconds, and allows Thresh to dash in and chain it with the rest of his CC. Its range makes it hard to cope with Thresh in losing matchups and exerts a lot of pressure over the opponents in lane knowing they can't get too close to farm while Death Sentence is up. But while he shares many characteristics with melee supports and is a great deal tankier than enchanters and mages, he's still notably squishier than the average melee support and has a harder time surviving all-ins and being caught by CC in even or bad matchups.
Vel'Koz provides some of the longer range poke of all the mage supports, with experienced Vel'Koz players also being able to easily land poke on targets hiding behind minions due to the way Plasma Fission works, making it hard to avoid the pressure Vel'Koz exerts over a lane.
He also brings long range massive AoE damage in Life Form Disintegration Ray after level 6 which makes it hard to ignore him in fights, while his range also makes him a hard target to get to. He also has a displacement CC in Tectonic Disruption to keep himself safe with, covering all his bases and making sure there's no easy way to deal with him in lane.
Xerath is the most oppressive mage support in lane despite not being too popular in the role. Neither of his two poke spells are hindered by minions meaning there's no way to avoid his poke except by dodging it, and since in the support role he doesn't have to move into a vulnerable position to last-hit there's not much room to fight back unless he's comfortable enough to step up because he thinks he'd win the fight. As far as mage supports go though he's probably the most vulnerable.
He does have CC in Shocking Orb but it's not a displacement, is single-target, has a short duration at short distances such as when the engage has already happened, and while his poke is the most oppressive of any other mage support he also has the least immediate burst of any mage support so there's generally very little risk in engaging on him in even or close to even circumstances as he won't blow up one or two people at a time like Zyra or Brand could.
This makes long range engage supports a lot more effective at dealing with him than they are against other mages. Which is not to say that they beat him, since in a vacuum Xerath should basically win lane against any support except for maybe Pyke, just that they fare better against him than they do against other mage supports despite Xerath being the strongest laner of them as a whole.
Yuumi is extremely squishy and as such has to spend the vast majority of her time attached to her ADC in order to not get constantly caught out. She provides a lot of healing and poke while attached but while it gives her an amazing late-game, for laning phase it doesn't quite make up for the lane being a 1v2 most of the time as she lacks lane presence, both literally and figuratively.
She fares worst against engage supports who can both force her to detach less for fear of getting CC'd and blown up in an instant and also abuse the fact that her lane partner is sort of 1v2 and easy to engage on most of the time, but tends to perform quite well into other enchanters or weak laning supports who can't abuse her lack of lane presence, and also can't abuse her as hard when she's detached which allows her to detach more often and have more lane presence than she would in tougher matchups.
Zilean is similar to Karma in that he acts as a sort of mix between an enchanter and a mage, though I would personally say he leans far more onto the enchanter side, and it shows in his laning strength, or lack thereof. Like Karma he has rather high damage poke in the form of Time Bomb which also provides an AoE stun as well as doubling its damage if he resets its cooldown with Rewind and lands it twice. The issue is that it's very hard to lane compared to Inner Flame or other poke supports' abilities, and to obtain its full benefits he needs to manage to land it not just once but twice within a 3 second period. When successful he's very highly rewarded, but otherwise he's rather underwhelming.
He can make it much easier for himself to land a double Time Bomb by casting Time Warp on his intended target, but this has a rather short range which leaves him open to retaliation. This means that when facing weak lanes he's more likely to be able to walk up to cast Time Warp for easy double Time Bombs, but in harder matchups where he can't walk up to cast Time Warp without being punished he won't have anywhere near the same level of poke and overall lane presence, leaving a rather large gap between his highs and his lows in laning phase.
Following and finishing the mildly amusing trend of most mage supports being located towards the very end of the alphabet, Zyra is just as lane dominant as the other mage supports, providing very high lane presence with her poke and burst, though compared to other mage supports she sacrifices a little bit of poke to make up for her high CC in her AoE knockup on Stranglethorns, and her high DPS in Rampant Growth and Garden of Thorns .
Her poke is also significantly on the shorter range which leaves her slightly more vulnerable to low range engage supports, while in winning matchups not being as much of a problem against long range hook-based engage champions who need to path around minions to find her and leave themselves open to eating up one of her combos, but limiting her ability to poke in losing matchups where she has to stay far away from the minion wave and can't poke without also being at risk of getting engaged on.
However she's very strong in all-ins where she can get her full combo out thanks to the DPS she gets out of her plants, especially when buffed by Stranglethorns, and also her combined 2-3 seconds of CC that prevents the targets from escaping the DPS coming from her plants, making engaging on her a scary prospect if her enemies can't burst her down before she has time to get her full spell rotation out, as while they may very well be able to kill her there's also a good chance that with the help of her ADC she'll take 1 or 2 of them down with her.
Understanding How Two Bot Lanes Match Into Each Other
It's a complicated subject since there are some champion synergies that need to be accounted for, but generally a duo's strength will be the sum of their parts. So a high threat ADC with a high threat support would be a high threat bot lane, but a high threat ADC with a low threat support would be a medium threat bot lane, and a medium threat ADC with a high threat support would be a medium-high threat bot lane, somewhere in between; but of course it's all relative so sometimes a medium-high or even just a medium threat duo can be incredibly oppressive towards low-threat bot lanes, depending on the particular matchup.
Drafting Your Bot Lane
Drafting a low threat bot lane is one of the worst things you can do into a medium-high+ threat bot lane. If you have the time feel free to look over this VOD review, otherwise I'll summarise it for you: the matchup is Caitlyn-Bard vs Kai'Sa-Janna. Janna on her own is pretty middle of the pack/low threat on her own when it comes to trades, while Kai'Sa has the potential to deal a lot of damage in all-ins but is very low threat outside of all-ins. Meanwhile Caitlyn and Bard are both long range, trade heavy bot laners who suck at all-ins but are hard to engage on without engage spells like Death Sentence or Zenith Blade.
While Janna-Kai'Sa isn't a particularly bad bot lane into low-medium range trade-focused champions and there are worse bot lanes for dealing with all-ins too, they're awful into a trade-focused medium-high threat bot lane like Caitlyn-Bard as they lack the tools to deal with them, they can't win trades since they get outranged so hard so their only way to fight back is through all-ins, but while they would win an all-in if they could actually force one, neither of them actually has the tools to force said all-in against this matchup. Give Kai'Sa a Thresh instead and they could heavily threaten the Caitlyn-Bard lane and force them to play more respectfully, but instead her support is Janna, bringing their overall threat level down to a point where they pose no threat at all to the Caitlyn-Bard lane.
The result is Kai'Sa-Janna get their waves shoved in under tower repeatedly, and while they do get a few Rengar ganks to help them out, some counterganks and outplays from the opposing team leave them stuck in their complicated scenario, resulting in their tower falling at 9 minutes and being over 20 CS behind from all the CS lost to tower.
But the onslaught doesn't end there. Caitlyn-Bard rotates to top lane and Kai'Sa-Janna have to follow them since they stand a better chance of defending the 4 platings tower than top lane Kennen does 1v2. But 2 minutes later the top lane tower also falls, Caitlyn-Bard having now claimed two separate towers single handedly by the 12 minute mark.
They proceed to rotate mid lane and repeat the process there, and it all snowballs into Caitlyn-Bard's team claiming every non-inhibitor tower on the map by 16 minutes while their team hasn't even lost half the HP of a single tower. All because Kai'Sa-Janna drafted a bot lane that had no answers for a long range trade-heavy bot lane like Caitlyn-Bard.
How could this have been avoided? Either a change in the ADC or the support could have drastically altered the outcome of the lane:
Looking at Supports
Thresh would have provided a lot more pressure to scare Caitlyn-Bard away from permanently auto-attacking the tower and also could have potentially won them lane priority if neither Bard nor Cait could risk getting hooked for fear of dying.
Brand's harass would have provided enough pressure to stop them completely free-hitting the tower for fear of falling too low in HP, and possibly won over lane priority if Brand landed enough of his spells, especially given that his all-ins when landing Sear are pretty scary due to his burst, even before he has Pyroclasm.
Morgana wouldn't have won over lane priority but would've introduced the fear of getting binded and provided the ability to force an engage onto a snared target without fear of being immediately stunned by Cosmic Binding thanks to her Black Shield, again not allowing them to hit tower as freely as they did, while also providing far better gank assistance than Janna did.
Looking at ADCs
Draven would have manhandled anyone who dared to get into his range, Cosmic Binding be damned, since his spells give him the ability to engage just by walking up with high movement speed and briefly CC'ing his target with Stand Aside, Bard especially would have been particularly vulnerable to this while Caitlyn is a bit safer with 90 Caliber Net but also has to be afraid of being abused by Draven if she misses the slow.
Varus could have snared either opponent close to tower and used that as an opportunity to all-in at the very least getting free damage off, and also makes Caitlyn-Bard much more scared of ganks knowing that getting hit by Chain of Corruption would mark their death and minions offer no protection against it.
Tristana would've also had far better gank followup and also far more threat in all-ins while also having the means to engage herself, again demanding far more respect from Cait-Bard than they had to offer against the Kai'Sa.
What Does This Mean?
As you can see, neither Janna nor Kai'Sa in particular was the problem, nor are they necessarily a bad bot lane duo in general. But the world of bot lane matchups is a complicated one and, either because of having had to blind pick or intentionally drafting their duo into Caitlyn-Bard out of ignorance, their bot lane duo resulted in disaster that particular game. Replace Janna with most low threat supports and the same thing would've happened, replace Kai'Sa with most low-threat ADCs and the same thing would have happened.
I would hate to write a traditional matchups chapter for bot lane because it's never as simple as "Caitlyn beats Kai'Sa" or vice versa, it's highly dependent on the bot lanes as a whole. Reverse the supports and Caitlyn still would've won but probably not as one-sidedly, replace Janna with Nautilus or Thresh and Kai'Sa probably would've been favoured as suddenly they have the tools to capitalize on Caitlyn-Bard's weakness to all-ins.
SYNERGIES EXAMPLE: Lucian + Braum
Of course you also have to account for synergies between champions, but you also need to remember that synergies between champions also tend to be heavily overrated. The
first example that comes to mind is Lucian-Braum, their passives' interactions with each other are insane as Lucian's passive very quickly stacks Braum's passive, and this has given them the reputation of being a brutal bot lane matchup to face.
But Braum is one of the weakest laning supports in the game, and his synergy with Lucian doesn't change that. Out of all the supports in the game, Braum is Lucian's 3rd worst performing support in lane where he causes Lucian to fall 250+ gold behind by 15 minutes in the average game when he's a lane bully who should be ahead in lane, while Lucian paired with some of the high threat supports yields a 400-700 gold lead at 15 minutes for Lucian on average. In winrates they're also an awful duo because Lucian is one of the weakest ADCs at the time of writing this and Braum has been one of the weakest supports for a very long time when writing this too.
A bot lane doesn't necessarily have to shine at the same points, you can pair a strong laning support with a weak laning support, and despite sounding like they have counter-synergy it actually results in a medium-threat bot lane while also having medium-scaling, which you generally don't get from high threat ADCs/supports who tend to fall off. Despite having opposite focuses, the result is a happy compromise between those two focuses, and not necessarily a bad thing unless your team comp really needs a winning bot lane and the enemy bot has drafted an even stronger lane.
So Braum being a weak laning support while Lucian is a lane bully doesn't innately mean that they're a bad duo, each individual's strengths in theory are meant to cover up their weakness
while the reverse also applies and leaves them a perfectly viable but not overpowered option; but their weak tuning does make them a bad duo. They're both individually weak and their synergy doesn't make up for it. When you're playing Lucian, you'd rather have a strong support you have no synergy with than a weak support you have strong synergy with. If you're playing Braum the same thing applies, you'd rather have a strong ADC you have no synergy with than a weak ADC you have strong synergy with.
If they were both buffed to a point where they're strong in solo queue then they'd become a great bot lane, but as it stands they're one of the weakest bot lanes in the game, but remain heavily overrated year after year because people overlook their tuning when looking at their synergy, and forget that synergy isn't the only thing that matters, and in this case there's a bigger factor overriding their synergy.
SYNERGIES EXAMPLE: Twitch + Lulu
Another example is Twitch-Lulu, which especially with the rise in prominence of funneling has enlightened the world as to what a terrifying duo Twitch-Lulu can be. But when
you look at solo queue performance, Lulu isn't even Twitch's best support, even though Twitch is Lulu's best ADC (though not by a great margin over #2 or #3). She's consistently very close to the top, ranking from #2 to #4, but not on a single patch is she ever actually his best performing support, an honor which is split between Nami and Taric, slightly favoured towards Nami.
This is because while Lulu is the support which best enables Twitch in the mid-late game by massively boosting his DPS and also providing incredible protection from divers and assassins, she's also one of the weakest laning supports in the game and Twitch is also one of the weakest laning ADCs, which means if you were to just constantly pick them every game you'd very frequently find yourself in scenarios like the Kai'Sa-Janna from earlier where you're too weak to do anything and fall massively behind with no options to fight back.
Whereas Nami is also an excellent scaling support, and while she doesn't scale as well with Twitch as Lulu does, she makes up for it by being far better in lane, especially in those scenarios where you're facing Caitlyn-Bard or similar bot lanes, where Tidal Wave and Aqua Prison give her an excellent engage tool to allow Twitch to open up from stealth and burst down bot laners that just want to maintain their distance and force short trades, and also has heals to keep him healthy and in a position to force those fights rather than being too low to threaten an all-in.
Whereas Taric is probably just as weak in lane as Lulu if not more, but again has a much better engage tool especially paired with Ambush, and has an all around much better performance in all-ins after level 6. Then while his scaling with Twitch in particular isn't as good as Lulu's, his contribution to the team as a whole lategame is much better than what Lulu offers.
All these factors are mainly what lead to Nami and Taric on average performing better with Twitch than Lulu despite Lulu having far more synergy with him. There are definitely scenarios where Lulu is a better pick, for example if you're facing a low/low-medium threat bot lane like
Kai'Sa-Janna then bot lane is probably going to be a farm fest above all else so Lulu will perform much better than she would into stronger bot lanes, but again this example serves to show just how fluid the bot lane ecosystem is. X pick is not always going to be the best counter to Y pick, V pick is not always going to be the best pair for Z pick.
It's not commonly talked about and I believe it's also a very poorly understood subject even at the Challenger level, where even Challenger players sometimes think a Soraka-Twitch lane can beat a Tristana-Rakan lane by poking them down, like Tristana-Rakan doesn't have the ability to one-shot either of them on demand the moment they get in range to poke; while Soraka poking down Rakan would actually be a viable prospect if Rakan were paired with Kai'Sa, against Tristana trying to poke is just suicide.
Bot Lane Matchups & Duos Conclusion
It's impossible to discuss every single possible duo against every possible duo, so a lot of it is going to ride on your game knowledge and experience. The purpose of this chapter was to provide you with as much relevant game knowledge to understanding bot lane matchups/pairings as possible, and I hope it has done so. You will still require a lot of experience to perfectly understand how different duos will interact with each other while also accounting for how the different players perform, but unfortunately that's beyond what a guide can teach you. At the very least though I hope I've at least set you on the right path.
You'll want to take Icathian Rain at level 1 since it's your best trading tool and can slightly help you push.
When you get into lane, you should spam auto-attacks on minions to push as fast as possible to beat the enemy bot lane to level 2. You can try and poke the enemy ADC with free auto-attacks if a good opportunity arises, but for the most part you shouldn't be actively seeking these and should instead just focus on pushing faster than the enemy bot lane.
Whichever bot lane starts losing the push should begin to back off once they've clearly fallen behind in the push, to avoid trading against the bot lane with the minion advantage. Should the enemy bot lane be the one backing off, at this point you don't want to keep pushing, but rather begin to freeze by only auto-attacking the minions to last-hit.
This is for two reasons: the most obvious reason is that when your minions get low from being auto-attacked by the minions you're intentionally leaving alive, the enemy ADC has to walk towards you if they want to last-hit it and take free poke in exchange, and rather than do that they will instead choose to miss that CS, placing you at a CS advantage. The second reason is that while you want to push for your level 2 powerspike, your level 2 powerspike is useless if you push the enemy bot lane safely under tower. You want the minion waves to stay as close to the middle of the lane as possible, so that when you hit level 2, if the enemy bot lane don't let themselves be zoned far enough away you can just all-in them for a kill, or at least chunk them for a lot of damage. Good minion wave management at this stage will have you winning the level 2 race without the minions budging from the very middle of the lane until later.
Should you find yourself losing the race though, you should back off when the enemy bot lane is approaching level 2.
At level 2 you'll be leveling Supercharge to increase your mobility, which can be useful if you need to reposition, chase, or escape a gank. At level 3 you'll want to take Void Seeker for the extra damage.
Depending on the matchup you may either want to freeze the lane and zone the enemy bot lane with the threat of trades/engagement, or shove them in repeatedly harassing them and their tower, which works best when you have a mage support that can pressure the enemy under their tower. Freezing works best when you have a good engage support so you can more efficiently zone the enemy from the wave and they have no tower to protect them if they get engaged on.
Whenever you're shoving under tower and can't poke anyone with auto-attacks, you should be auto-attacking the tower to make sure it goes down as soon as possible, since it's a +650g boost in power for you if your team allows you to take full local gold.
Out of Lane
Outside of laning phase, your objective is to destroy the nexus. No I'm not kidding, that's literally the best way to describe it. Every action you take in laning phase is to set you up for mid-late game, every action you take outside of laning phase is to bring you one step closer to destroying the enemy nexus. The way you do this is by performing actions that will make killing the enemy team easier (acquiring gold, dragons, barons) so that you have less resistance, and destroying towers as a way to acquire gold, have better control of the map, and open up routes to the nexus.
At this point you should be grouping with your team as much as possible to teamfight and siege down towers. Kai'Sa isn't the greatest sieger due to her low auto-attack range with little poke/zoning power,
so be aware that you're going to be more at risk and not as effective as some other ADCs.
Sieging towers is pretty simple, but you need to be careful about it. When both teams are alive and your team is trying to take a tower, it's your job to do as much damage as you can to the tower without dying. You need to do as much damage as you can while remaining safe. This means you can't just walk up to the tower and stand there auto-attacking until it dies; this leaves you open to get engaged upon, unless there's no resistance from the enemy team. Instead you have to repeatedly poke the tower. Walk up to it, attack it a bit, back off if someone dangerous is walking up to you.
Now you might think "but what if they never stop protecting their tower? Doesn't that mean it's never safe for me to auto-attack it?". If they're constantly standing in a defensive position in relation to their tower, then they're most likely to be in range for your team to poke them and force them back. They need to be in a place where it's safe for them to sit and look for a good engage, where your team has no way to attack them without tower diving them. And if they advance, that takes them further out of safety, so if you match their movements to stay safe from an engage, they'll be forced to move back for their own safety again, as they don't want to get engaged on in a bad position either, nor poked down to a point where they need to recall to recover their HP.
So you should think of sieging as slowly whittling down a tower. It almost never takes a single minion wave to destroy a tower (unless you have baron buff), it can take many, many waves, but slowly but surely, the tower will go down if you can siege it properly.
When you're attacking a tower with enemies nearby you always want to be positioned at max distance from the tower while you auto-attack, and in between auto-attacks you should move backwards then forwards, so that while your auto-attack is "on cooldown", you're not spending any more time closer to the danger than necessary. It's also good habit in case they start to try an engage and you're already automatically moving backwards the moment you finish your auto-attack, meaning you'll often protect yourself from an engage faster than you can actually react to it, so long as you notice in time to not move back towards the tower for your next auto-attack.
Against teams with very high wave clear (hello Anivia), it can be very hard if not impossible to siege down towers, especially inhibitor towers that actually recover HP all the time. Your options in these situations are to engage on the enemy team under their tower (which only works when you're reaaaaaaaally far ahead), get another lane to slow push then rotate to it when the wave is reaching the tower, or go get baron. The enemy team won't usually just give up baron for free though, and so you can use this to bait them into a fight. They'll need to constantly have vision on baron to make sure you're not doing it, which can be hard to keep up if your team places Control Wards and uses Oracle Lens to clear their wards, so at some point they might have no choice but to face check baron to make sure you're not doing it. Even if you are, you can take the opportunity to turn around and team-fight, so long as your team hasn't become too low to fight.
Ever wondered how pros can get 300 CS at 30 minutes before? No, it's not completely down to "insanely good last-hitting mechanics". You can do it too, just by using a simple wave control technique. Watch this video to understand how minion waves work.
So when 2 minion waves collide on bot lane, in the middle of the lane, you should be there to push those 6 minions. And then you leave bot lane. No, you don't stay to push the 2nd minion wave too and force your wave to hit the tower. Aside from being at risk if you do that, it's also just not smart to do it. Because once you clear the first wave and your minions advance to crash into the next minion wave, your minions will be on the enemy's side of the map, and as you just learnt from the video, that means that the wave will slowly but inevitably start to push towards your side of the map.
After clearing that first wave you just go pressure mid or teamfight or whatever, then you just return bot lane in 2-3 minutes when the enemy minion wave has finished pushing to your tower (and make sure to get there before the minions start dying to the tower). At that point it'll be a 15-20 minion wave. Assuming it's 20 minions, and you've been off of bot lane for 2 minutes, you'll be getting 20 minions for the 2 minutes you've spent off lane, keeping with the 10 cs per minute rule you always want to aim for (though won't always be able to achieve).
But even if it isn't quite 20 minions, the time that you've spent off of bot lane, you'll have spent farming mid lane, and maybe even jungle monsters. You'll essentially be farming 2 lanes at once, keeping you easily above the 10 CS per minute rule so long as you can consistently get to the bottom lane wave in time before the minions start dying to the tower. This won't always be possible, as CS isn't the most important thing in the game. Sometimes you'll be busy teamfighting, or making sure you're around in case a teamfight starts. But in general you'll want to go farm the wave as much as possible, then push the wave onto the enemey's side of the map to restart the push, both to get ahead in farm and to avoid having a huge minion wave destroy your tower.
When the wave that you're pushing is a cannon wave, that messes with this technique a little bit. Because you'll be killing the enemy cannon minion and letting your own cannon minion push uninterrupted, the enemy minion wave won't slowly push up to your tower. Instead your minions will continue to push forwards, very slowly. When it's a cannon wave, you should either push the 2nd wave too (if it's safe to do so, not at all safe to do when the enemy team is ahead in towers and enemy threats are unaccounted for on the minimap), or just recognize that you won't be able to get the wave to push back to you in this specific situation and settle for creating a slow push instead, rather than trying to create a farming opportunity for yourself later on.
The video also explains how to create a slow push, but this technique is very rarely useful in solo queue with how uncoordinated everyone is outside of very high Elo. Keep it in mind in case you ever think it could be useful, but most of the time it just ends up creating a huge minion wave for the enemy AD carry to farm, getting him ahead in farm instead of you. It's better suited for ranked 5s assuming your team understands the strength of a slow push, or if you're a high Challenger player and for some reason reading a MOBAFire guide.
In some situations, notably when you expect to be sieging for a while and especially sieging towers that are really close to the enemy base, such as inner towers and inhibitor towers, it's really not ideal to have to force yourself to go back bot lane to farm every 2 minutes. If you do the technique and you can't go bot you'll essentially have just created a slow push against yourself, causing the enemy minions to die to tower, wasting gold, damaging your tower, and possibly even destroying it. Rather than putting yourself in that situation, this is when you want to create a slow push against the enemy team, as they'll hopefully be too busy defending against the siege to send someone to clear bot. This way they'll be the ones losing minions to the tower, taking tower damage, and possibly losing a tower if it's already low. And if they do send someone to clear it, you'll either have an easier time sieging or your team will be able to dive the enemy team 5v4 under tower.
When it comes to team-fighting as an ADC, there is one golden rule which is the most basic team-fighting rule of all, and yet makes you an infinitely better team-fighter if you start following it; attack whoever's closest to you. If you stand at the back, behind your frontline, and just auto-attack whichever enemy is absolutely closest to you, you have the best possible positioning, as you'll only be in focus range of whoever's diving you, or whoever you're attacking.
It's recommended in general to take down the enemy carries before the tanks, but as the ADC if you try to attack a carry then you're in range of every single member of the enemy team, and if they all focus you then you'll go down in under a second. By keeping your distance and attacking just whatever's closest, you'll be hardest to kill, and can therefore output maximum DPS by just staying alive and being able to auto-attack all fight long. The only time you should attack the enemy team's carries is when there's no other enemies standing between you and them or if they're horribly positioned themselves and you can focus them down along with your team.
The best players of all know not only when to follow that one basic rule, but also when to take even further measures to stay safe. Before you ever even get into a team-fight, you should have already analyzed what all the threats to you on the enemy team are, and play more safely or aggressively accordingly. For example, if a Shyvana is the one trying to dive you, you'd want to follow the rule of attacking whatever's closest, and just kite her while your team also hopefully tries to peel her.
But sometimes you need to turn the safety notch up another level and straight up walk away from someone that could be a threat to you. For example, if you're playing vs Zed, you cannot be one of the ones trying to focus him down while he still has enough spells and HP to be a threat. Even if he's the only person in range of you, and you have 3-4 team-mates around you, you still can't be auto-attacking him until the threat he presents has been neutralized ( Death Mark goes on CD, or he gets so low that he'd die before he could burst you). All the skill and mechanics in the world won't stop him bursting you down in half a second if he gets near enough. And you not only need to stay out of his Death Mark range, you also have to account for the extra distance he can cover with Living Shadow, Youmuu's Ghostblade and Flash, and how quickly they can help him close the gap.
No, when you're playing against Zed and you see him running in your direction, you stay as far the f**k away from him as you can get. Don't help your team kill him, that's not your job. The assassin's job is to kill you, your job is to not die to him, and your team's job is to protect you from assassins by killing them. If the assassin commits their cooldowns onto someone else when they realize they can't get to you, that's when it's safe for you to walk back into the fight. Or if the assassin gets CC'd and blown up uselessly before they get to do anything, then it's also safe!
Champions that present such a large threat to you aren't just limited to assassins ( Talon, Zed, LeBlanc) that can burst you down within a second. Other champions, mostly if fed, can just out-duel you so brutally, that even if you have 2-3 team-mates helping you in an effective 1v3/1v4, you're still going to die if they can get in range of you. Champions that can commonly do this when fed are bruisers like Irelia, Jax, Renekton, etc. Champions tanky enough to qualify as tanks while still dealing huge damage to a squishy target like you, especially when fed.
Against champions like these, it's really necessary for you to watch out and keep your distance. You can poke with Void Seeker and the occasional auto-attack while they're CC'd, but you can't fully commit to DPS'ing them down until again, they either fall so low at your team's hands that they're no longer a threat, or realizing that they can't get to you, they commit their most important cooldowns (mobility and/or CC) onto someone else. In Irelia's case, it's safe to commit onto her when she's used either Bladesurge, as she won't be able to gap close to you or burst you with it (though Flash may still pose a threat), or Flawless Duet, as it'll prevent her using her deadly stun on you. And if she's used both then until they come off of cooldown she presents almost no threat at all, so long as you maintain good positioning and kite if she tries to walk towards you.
When following the rule of "attack whoever's closest", often you'll have to choose between two champions that are at a more or less equal distance from you, and it'll be optimal for you to attack one or the other, but it's hard to be completely certain about who the right target is. That being said, here are some things for you to consider which will hopefully lead to you making the right choice:
1) Which is the bigger threat?
You'll want to take out whoever's the biggest threat not just to yourself, but to your team as a whole, and disregard the weaker enemy. Sometimes it's not very clear cut, others you have to choose between a fed Riven and a 1/1/5 jungle Sion, in which case it's a very obvious choice which you should focus.
2) Who would die faster?
When the targets are equally threatening, you'll want to focus whichever one is squishiest/lower HP, as the sooner they're out of the fight, the sooner your team gains a numbers advantage. Sometimes even if they're the lower threat, it's still worth focusing them down first if they're going to die significantly faster, but only sometimes, and it depends on how big a threat the other possible target is.
3) Who's least likely to get away from you?
The less mobile one is the least likely to walk away and succeed in getting away. You'll want to focus the least mobile one as they're the ones most likely to die if they get low. A tank with gap closers like Zac (and let's just say his passive isn't up so you don't need to worry about that) may get low, then just leave the fight with Elastic Slingshot before you can finish him off. If your other option is an equally tanky Sion for example, he's less likely to be able to get away alive when he gets low, so it'd be smarter to focus him in a situation where it's just as easy to auto-attack both.
Generally, from top to bottom those would be the most important factors to take into account respectively, but sometimes one factor, if it's big enough, can over-ride a generally more important factor. For example, choosing to DPS down a negative KDA, full AD Lee Sin, over a fed Irelia, because you can kill the Lee in about 2 seconds while the Irelia is a lot tankier, so takes a fair while longer to kill.
That's it for my Kai'Sa guide. I hope you found this helpful and learn to play Kai'Sa as well as you want to.
If you enjoyed this guide you may also enjoy Vapora's Guide To Tristana, a guide to one of my favourite ADCs. They have very different playstyles but I find Tristana fun to play as well. Otherwise you may still want to read it if you're wanting to improve your ADC skills because it's kind of like a general ADC guide as much as it is a Tristana guide.
Special thanks to Hopper for banners and coding, as well as some input on info.