Kog'Maw Build Guide by Aqua Dragon
Your votes and comments encourage our guide authors to continue
creating helpful guides for the League of Legends community.
+1-10% CDR (lvls 1-18)
+8 Magic Resist
+8 Magic Resist
Hi! I’m Aqua Dragon. I've been in Diamond for multiple seasons and I play AP Kog'maw.
I also play:
I also take people's suggested playstyles, optimize them, and then make guides on them!
Want to to discuss or watch this build?
- Gets exponentially stronger as the match continues
- Prevents damaged opponents from fleeing fights
- Reliably farms creeps from a distance
- Durable due to several HP-granting items
- Able to duel anyone late game
- Powerful objective defender
- Atrociously weak early game
- Has low mobility
- Low impact until Level 11
- Damage is sustained rather than bursty
- Pathetic objective controller
- Neverending greed for mana
Distributing Death in Moderated Concentrations
"Barrage Limit" is a term that will be repeated throughout the guide several times, and for good reason! It’s a fundamental part of playing AP Kog and impacts laning, teamfighting, and defending.
The ultimate’s mana cost goes up almost exponentially. Shooting 1 ult is a pitiful 40 mana, but shooting a full barrage of 10 bullets requires an enormous 2,200 mana.
This poses a problem. Continuing to fight requires constantly shooting, but constantly shooting drains mana. To maximize your time poking, you need to shoot just enough that your mana regen will have replenished more than the mana expended when your artillery stacks reset to 0, accounting for ult cooldown.
Or, more simply:
The number of bullets it takes to break equal with your mana regen is what I term as the Barrage Limit. The two examples above have Barrage Limits of 2 and 3.
It's a bit more than 10 seconds because the ult does have a 1-2 second cooldown between shots, and there's also time needed to line up the next shot.
Your Barrage Limit can be considered your guaranteed bullets. The rest of your mana bar is considered reserve bullets. The Barrage Limit eventually becomes instinctual, but initially requires a lot of conscious thought.
A final note: the Barrage Limit is not an exact science. You'll often find that you will lose 20-60 mana per barrage even if you stay at the Barrage Limit. However, it functions as a serviceable estimate. You can find out how to increase the barrage limit later in the guide.
Making the Rain Have Pain
There are a few extremely important, unintuitive things to keep in mind about AP Kog’maw for this guide to be of maximum effectiveness.
Scroll to the bottom of this section if you want the short version.
AP Kog’maw is largely a misnomer. Unless you’re at full build, your AP levels will hover around 100-200 AP even 40 minutes into the game.
This is because Living Artillery has a fairly unimpressive 0.25 scaling on it. The AP scaling does increase as the target gets lower health, but so does the base damage, meaning the AP-Base ratio stays awful. This makes AP an underwhelming choice compared to simply increasing the Barrage Limit or getting magic penetration instead.
But I'm not content just saying that. I put my math where my mouth is and created a damage efficiency kogculator to find out the most damage efficient pathway for AP Kog. None of the AP items came close to matching magic penetration alternatives.
This isn’t to say Kog has bad ratios overall; the other abilities have decent ratios. But AP Kog’maw is not dangerous due to their basic spells. If you’re looking for a mid-range AP champion, there are a wealth of others with significantly better damage, mobility, and utility.
Maximizing the base damage requires maximizing magic penetration and the barrage limit instead.
Hitting a person in a teamfight with one Living Artillery is easy. Hitting them reliably again is hard. The ultimate is designed to be entirely avoidable. Even if a champion is directly at the center of the ultimate, they are almost guaranteed to be able to run out of the AOE.
This means Living Artillery is at its best when someone is running away, forced to either stop moving or to get hit. But there is a casting time, and so they will outrun you as the casting time of the Ult prevents you from catching up.
To reliably chain ults on opponents requires mobility or CC. Reliably chaining ults dramatically increases fighting power. However, when you hit the point where you can outrun opponents while ult’ing, any additional mobility encounters diminishing offensive returns.
Earlier, the Barrage Limit was discussed. Namely, that flat mana only increases reserve bullets. With just Tear, there is usually sufficient bullets in reserve for most fights, as long as the Barrage Limit is not constantly exceeded. This make flat mana a less worthwhile priority; it only is used when really pushing the limits of the ult.
Mana regeneration is great, but limited. It needs to be sought out in other ways, primarily through killing Aqua Dragons and Blue Buff. But when these are acquired, AP Kog gets some very noticeable power. Every time you increase your Barrage Limit, you effectively increase your consistent damage output.
For itemization, this mostly means that building flat mana, for the sake of more mana, is not worthwhile.
Maximizing the power of the ultimate is the primary objective, and unfortunately, cooldown reduction fails at improving it much. Because the 10-second lockout at the end of the ult does not change with CDR, all CDR does is marginally increase how fast the ult shots go out.
CDR is useful for the other three abilities, but none of the three are good enough to justify investing too much itemization into. They aren't often used off cooldown in the first place.
CDR is still a decent stat, but not a high priority consideration.
Kog should be built to take maximum advantage of their high base damage, hefty range, and Barrage Limit. This means the stats Kog generally wants more than anything else are:
This guide is built around this mantra.
Take note this means you won't necessarily have a lot of early-mid burst damage. But this is okay because AP Kog is a sustained damage champion! Always remember this. You will often get comments like "you don't do any damage." This is because it is extremely easy to overlook sustained damage compared to burst damage.
You will almost always have one of the highest damages dealt in each match, so don't focus on the comments and focus on your aim.
Void Ooze makes sense as a first max for its powerful waveclear, increasingly nasty slow, and highest raw damage output besides Living Artillery.
AP Kog is able to get off some reasonable autos so it seems tempting to max Bio-Arcane Barrage next, but this is a trap. Here's some numbers.
Bio-Arcane Barrage offers 3% max health damage on-hit at rank 1, increasing to 6% at max rank. In addition, without an AS item, AP Kog has a little under 1 auto per second.
So what’s the DPS increase from rank 1 to rank 5? Well, 3% of 1000 HP is 30 damage. After 5 ranks, this damage increases up to a whopping... 60 damage. Which means for four rank ups, that’s an increase of little under 30 premitigated DPS.
With 3000 HP that DPS bonus goes up to 90 DPS, which sounds great, but it’s also competing against Caustic Spittle’s three benefits from rank 1 to 5:
- 200 extra base damage (more burst)
- 20% bonus AS (more DPS)
- 8% stronger Armor / MR shred (more teammate damage)
Kogulated Rune Choices
Unsealed Spellbook beats the keystones of other trees (this is addressed further, below this rune choice section)
Magical Footwear handily stomps the alternatives, no contest.
Biscuits extend the laning phase, drastically increasing gold and EXP gain.
Approach Velocity's mobility is a nice plus, and it beats both alternatives readily.
Overgrowth bulks up AP Kog even further, building on top of all the health items, making AP Kog a durable cannon.
Conditioning helps bulk up AP Kog past laning phase, which is when AP Kog most needs it. It's better than Bone Plating even without any additional Armor or MR items.
Scaling CDR, Armor, and Magic Resist
Following the priorities listed in the Critical Knowledge section provides us these choices.
If these rune choices seem strange, you're right! Isn't this an AP Build?
These choices make much more sense if you go back a bit to the Critical Knowledge section. Those priorities are being put into practice here. As a reminder:
Let's take a look at the trees using this metric.
Many of the runes involve giving ability power. But as detailed in the Critical Knowledge section earlier, raw AP isn't a great stat on AP Kog overall.
This indirectly hits Arcane Comet too, which has a very weak base damage of 30-100 with a 0.2 AP scaling. Without burst or without AP, it is a very middling rune, rarely being the reason that many kills end up being secured.
Meanwhile, Transcendence offers CDR, which isn't a stat that AP Kog wants either.
Scorch does add base damage by comparison, but it's clear that it is intended for lane harass and not for sustained poke. For sustained poke, it adds an awful 1-3 pre-mitigated DPS. Ew.
Celerity is effectively worthless on AP Kog, who will get only a pittance o extra movement speed from the boot bonus and nothing else.
Manaflow band looks super tantalizing. 250 mana and 1% missing mana per 5? Doesn't AP Kog love mana?
More mana regen is nice, but let's put this into perspective. Killing an Aqua Dragon grants 4% missing mana per 5. The Aqua Dragon is great, but is only enough to increase the Barrage Limit by 0.75. Meanwhile, Manaflow's regen is 4x weaker than the dragon. That's not even a fifth of a Barrage Limit increase!
The flat mana is convenient for reserve bullets, but that's about it. Mana regeneration is what AP Kog really wants. Plus, Biscuit Delivery conveniently gives a similar 160 mana!
This rune looks very tempting, but keep mindful the priorities: CDR is effectively meaningless for the ult, and flat mana has little value compared to mana regeneration.
Presence of Mind is akin to a flat mana boost, and in most situations will only ensure one extra ult, and even then only if the mana bar was already about to hit empty. It's an okay rune, and that's all.
These are okay.
AP Kog doesn't autoattack in combat that much, so this is just okay.
That's ultimately the problem with the Precision tree. It's just okay. Completely removing the weakness of AP Kog with Resolve secondary is significantly more impactful than just some okay runes inside of the Precision tree.
Everything boils down to this: Manaflow Band is the only worthwhile rune in the Sorcery tree for AP Kog, and even that's aggressively mediocre. Even the keystone is meh. This easily makes Inspiration the primary tree of choice.
That could maybe justify it as a secondary tree, but the survivability offered by the Resolve tree offers more impact.
Significant survivability > piddling mana regen + some AP
Meanwhile, Precision is just okay. That's not good enough. Invalidating one of Kog's weaknesses matters more than accentuating the strengths slightly.
There are too many flash-combos that even your max range can’t protect you from. Flash helps equalize the field, using flash to avoid dying to flash-combos
When flash is on cooldown, this is your second equalizer against flash-combos. It also prevents you from being towerdived by the mid and jungle. Later in the game, you are able to duel nearly anyone if exhaust is up.
Ghost is okay. Exhaust is better in almost all situations, but Ghost has use when with compositions that are explicitly structured to mitigate Kog's weaknesses and keep 'em safe even during the laning phase.
If you’re in range to Ignite, you shouldn’t be.
Useful too, but Exhaust has more impact at all stages of the game for surviving and dueling power. Heal and Barrier are great options to switch to with Unsealed Spellbook however.
Priorities in Practice
At the beginning of the guide, we established the priorities Kog has.
Additionally, I created an AP Kog'maw Damage Efficiency Calculator (TM) to find the optimal damage output for the least amount of gold. I found the total damage of any set of spell casts, which was divided from the gold spent. The Gold Spent For Each Point of Damage, also known as Gold/DMG, also known as damage efficiency.
Damage Efficiency (not to be confused with gold efficiency) is a great metric. Rabadons may give the most raw damage, but it is also an insane amount of gold. What if Sorc Shoes provide half the damage at a third of the cost? Then Sorcs would be the better bang for buck.
The build order is the culmination of all that.
Elaborated on further down. Refillable nice against unforgiving lanes.
→ → → → → → → → → →
You are seeing that right. Triple Rubies. They makes AP Kog practically unkillable during laning when the damage doesn't matter yet anyway.
Tear and Orb are not upgraded until the very end due to how poorly AP Kog uses AP.
Doesn't Have a Nice Ring to it
This start may initially seem confusing. Why no potions? What about Doran’s Ring?
First, potions are not free. Each potion costs 50 gold, which is about 3 minion’s worth. Therefore, to have potions worth their cost, you need to get 4 more minions that you otherwise would have lost. Else, you are breaking even or worse, and the only gain is exp.
Second, Kog is so weak early and has such weak trades that it's not reasonable to free-farm. Any decent opponent is going to be constantly harassing Kog away every time they try to move in to autoattack the minions. If Kog is in range to be getting hit at all, they are are not far enough.
These two facts combined mean that if you buy health potions, you would have to put yourself in poke-range and yet still manage to get 4 more minions that you otherwise would have lost. This doesn’t happen. Your autoattacks are too weak, your early range too limited, and your spells too infrequent to get 4 extra minions while standing in range of being hit.
Potions may serve useful when learning AP Kog, but they’re a needless crutch once you become proficient at farming from max range, especially because optimal play guarantees that you’ll run out of mana way before running of HP, even assuming you get hit occasionally.
When you buy Doran’s Ring, you get it knowing that you’ll eventually have to sell it. The amount of money lost from buying and then selling it is 240 gold, or about 13 minions. To make the Ring worthwhile requires ultimately getting 14 more minions that otherwise would have been lost.
The AP component of Dorans is already negligible. Void Ooze, your primary laning ability, only receives a pitiful 7 damage increase. The AP increase will largely not increase your farming potential. AP also has little benefit for AP Kog later down the road.
Next, the mana component. Doran's Ring regenerates 1 mana per second, for a total of 300 mana over five minutes. To compare: Sapphire Crystal gives 250 mana. At level 5, Faerie Charm will provide 0.54 mana per second, for a total of 162 mana over five minutes. In total, the pair grants 412 mana over five minutes.
The question is now can you get 14 more minions, that otherwise would have been lost, with 60 more HP, +5 minion auto-damage, and less mana compared to the Crystal start? Probabbblyy not.
Dorans is built with a purpose, and that purpose is to get an edge for the laning phase. For AP Kog, who doesn't care about trying to win the laning phase, it isn't a great investment.
As with Doran's, you buy knowing you sell it. 70 lost gold, so you need 5 more minions that you otherwise would have lost.
As mentioned earlier, Charm will regenerate 162 mana over five minutes. With Void Ooze and Barrage, that can earn about 4 or 5 minions. Really what is being asked is: can you get 11 minions that otherwise would have been lost with the extra health with refillable compared to the charm start? Actually... probably yeah. Refillable ain't too shabby. I wouldn't recommend against it.
But Here is where experience must simply take hold: unless messing up, I always run out of mana before I run out of HP. This means mana is a much bigger limiter on the number of minions able to be farmed rather than HP.
I wouldn't fault anyone for going refillable flask, and for most cases it is suitable. However, proper experience makes it a needless investment, one that extra mana is better able to suit.
It's one thing to say that AP is really poor on AP Kog, it's another thing to prove it. In the build order section, I discussed using my AP Kog'maw Damage Efficiency Calculator to find the most damage efficient build path through the levels.
The results? Magic penetration is absolutely amazing. There is no raw AP item that provides more power than magic penetration items on AP Kog'maw, even at low MR.
The following item choices were then judged on the damage efficiency metric.
A large mana pool is important to make sure reserve bullets are always ready later in the game. Tear also increases the Barrage Limit by 1.
A mixture of magic pen and mobility, a godsend for Kog’maw. It's tough to imagine any better combination that Kog would like.
The most damage-efficient magic-penetration item for Kog’maw! Great as a standalone pickup, and also adds a Ruby Crystal to the build to make AP Kog even more durable.
The second-most damage-efficient item for Kog’maw! Its high base damage adds tremendous power during all fights and allows poke damage to start racking up more meaningfully during sieges.
After Liandrys, the third-most damage-efficient item for Kog'maw! Allows access to chaining, making teamfight power significantly scarier; essentially boosts mobility in offensive situations.
The fourth most damage-efficient item for AP Kog'maw! It also fills out the build completely at six items. Still is damage efficient even to targets with base MR, while adding tank-busting autoattacks with Bio-arcane Barrage.
Terrible damage efficiency, but provides a good amount of mana, a shield, and CDR. All lower-priority, but still useful on AP Kog. Relegated to a much later purchase
The damage efficiency is so terrible that it severely gimps power. Plus, with a six-item core, there's no room for Banshees without delaying damage immensely.
The damage isn't good enough to justify getting. Without a lot of AP, there's not a lot of additional hits being added on. It's less damage efficient than Nashors, which itself isn't damage efficient enough.
Magic penetration is higher on the priority list. Rylais is usually enough offensive mobility.
That's Off the Chain
When Kog has Rylais, they gain access to one of their most powerful and flashy tricks: chaining.
Chaining is using CC to ult a target back-to-back with Living Artillery.
Normally, chaining is hard. An opponent is able to dodge Living Artillery simply by stepping outside of the landing spot. But with Rylais, if Kog lands just one artillery, it almost guarantees that the next artilleries will land.
After landing the ult, continue aiming the ult a little ahead of the opponent’s running direction. This forces two decisions: get hit by yet another ult or momentarily stop.
Stopping is no safety. A person who has to momentarily stop has put themselves closer to Kog. If they stop sufficient times, Kog will be able to reliably land an ooze-spittle combo, killing wounded opponents almost instantly.
Kog is not defined so much by “early, mid, late” as many other champs as far as their role is concerned. Rather, Kog’s power and presence is dictated by the rank of Living Artillery.
Before you have your ult, your laning phase should consist of using your spells at maximum range to farm the waves.
- Unless your opponent screws up, you will not win in CS
- Without potions or Dorans, Kog's effective gold is higher than the CS implies.
- Survival is the name of the game
- Don’t bother pushing hard. Autoattacks are like butter slapping a brick.
- If you die, you weren’t playing carefully enough
- Poke to farm
Don't Bother Trading: It doesn’t matter if they’re melee, if they have less range, or even if they’re out of mana. Every spell, every auto should be focused on trying to farm above all else. Your kill potential is fairly nonexistent pre-6. If you think you can kill them by hitting them enough? That's precisely when everything will start going wrong.
Land Incidental Damage: You may not be trying to poke opponents down, but incidental damage is always nice. Try to position yourself to hit both the minion and the opponent at the same time.
Beware the Enemy Jungler: Kog is such an easy target for the jungler to jump on. This is the biggest reason why even poking is fruitless; a competent jungler will take advantage of your vulnerability even if you’re only a quarter of the way down the lane.
Beware Your Own Jungler: Survival is your primary priority. Unless you have a jungler with a mixture of heavy CC and heavy damage, consider informing your jungler to not even gank for you. Kills rarely result unless the jungler has red and you can land a well-timed void ooze or exhaust. But even this opens up the fight to a countergank that is easy to lose.
Go Back Instead of Pushing: Your pushing power is stupidly weak. Even two uncontested minion waves won’t bring the tower to half health. It’s not worth the risk unless their jungler is in a different lane. Aim to rush the Triple Rubies for even more survival.
Get a Control Ward Against Flanks: Get an early control ward and set it up to protect from a jungler tower-dive ambush.
Always Improve at Surviving: Every death is preventable. It means you were too far without wards, you were trying to trade, you didn’t dodge enough, or you got surprised by burst damage. Take every death as a learning experience of what to expect for the future and avoid repeating the same mistake.
Use Unsealed Spellbook to Stall Longer: The two best spells to swap to early on Unsealed Spellbook are Clarity and Teleport. The first to stay even longer in lane before recalling, the second to double-dip refill on health + mana or to try countering a roaming foe.
The first rank of the ult is your first major power spike, immediately doubling your power. Upon receiving it, your Barrage Limit starts at 1.
- Prevent opponents from roaming
- Be cautious about roaming; it's often better to refill on mana
- Force squishy targets back with powerful ooze-ult combos
- If you die during laning, you weren’t playing carefully enough.
- Use your basic spells primarily for their utility
- Poke to deter
Ward the Enemy's Half of the Lane: Your opponent will likely have their ult at this point as well and will often begin roaming, as Kog lacks the pushing power to take advantage of their disappearance. Putting wards on their side of the lane will ensure that if they begin roaming, you can warn which direction they go so your team will have heavy advance notice to get away.
Be Careful When Following Roams: You may sometimes want to chase after roaming opponents, but be aware that they may easily be hiding around a corner or in a bush in ambush, waiting to take advantage of your still-weak power. Alert your team, and be extremely cautious of ambushes if you choose to follow them.
Avoid Roaming: It's tempting to roam yourself, but you're usually better off just being more focusing on farming up to Level 11. It may be self-centered, but it's not selfish, because it is the action that maximizes your entire team's chances of winning.
Use Ooze + Ult to Clear Minions: If you use Void Ooze on the caster minions, the execute bonus of the ultimate will proc on them, allowing an instant clear on the minions at later ranks of Void Ooze.
Deter Enemies With Ooze + Ult: Unless your opponent is very squishy, you should largely be using poke as a form of deterrence rather than a form of killing. Still, a successful ooze-ult combo on an opponent can deal substantial damage so always keep an eye out for chances to land one.
Unsealed Spellbook Provides Durability: Good swaps at this point start being Barrier and Heal, which add even further bulkiness. Between triple Rubies, Resolve Tree bonus HP, Boneplate, and Overgrowth, this is one well-carapaced Void monster!
You have hit your second major power spike, doubling your power once again. Now that you are 4x more powerful, you may begin poking very offensively at the opponents.
- Keep everything constantly warded
- Clear waves instantly and begin pushing and grouping
- Be wary of dash-combos
- Poke to kill
Keep Mindful the Barrage Limit: Don't go trigger happy with ultimates. While the Barrage Limit is about 2 now, be conscious of how much mana is being depleted. Running out at the wrong time can give the enemy leeway for a tower.
Use Spittle First: Caustic Spittle, Ooze, Ult, Auto. A committing target can’t avoid the Q, which will amplify the damage from the rest of the combo.
Chain Aggressively: Your teamfight presence is now massive even with few items. Rylais will be finished soon and you'll get to start chaining opponents down. Careful however; a wide variety of dash-combos can still reach you even at max range.
Scout With the Ult: Living Artillery grants vision on the location it casts on, so use it to see if the roaming mid-laner is trying to ambush you or if the opponents really are at baron.
Ult Your Feet: During duels against melee targets, keep ult’ing at the ground directly underneath yourself. This will guarantee the hit unless the target decides to disengage momentarily, buying valuable time to make distance.
Aim for the Zhonyas: Whenever you see someone has gone into Zhonya form, keep your eyes extra peeled on them and try to land an easy ult shot rightttt as the Zhonyas duration ends. Once you get good with the timing of your ult, the Zhonyas form is just a free target.
Unsealed Spellbook Provides Options: At this point, the summoners from spellbook will start rotating. Ghost is a good replacement for Flash when it's on cooldown while Smite can be used to help secure an objective, or just to add more CDR onto Spellbook. It's tricky balancing unique spells vs. more useful ones.
This is it. If you have made the game go on this long, another 2x multiplier in power. You are now 8x more powerful and boy does it feel damn good.
- Stay at max range unless an engage happens
- Keep a target locked on and shoot
- Destroy diving opponents
- Poke to win
Caustic Spittle the Tanks: Use your Caustic Spittle to slow down and shred tanks trying to dive into the middle of your team. If combo’d with your spells right after, a few empowered autos is enough to deal insane damage.
Your Dueling is Good: Your dueling potential is extremely strong if you have exhaust up. If the fight is starting to die down, consider getting closer to the fight and pick off the remaining opponents with your Bio-arcane autos, which now do fairly hefty damage in their own right.
Flash + Ult: Opponents will often try to break your chaining by flashing out of it. Flash toward them to immediately close the gap and continue chaining. Also use to get the last bit of distance to snipe a flee’ing opponent, but be wary that if they’re not CC’d, they can dodge the ult and waste your flash.
Use the Nexus Regen for Last Stands: In dire situations where you have to hold off several opponents from the nexus turrets, you are able to stand at the edge of the base regeneration and unleash a literally endless stream of bullets. This allows you to become the absolute final line of defense when things are looking grim.
Chain a Backline Target: You can safely pick targets every fight who you want to hunt down and chain them to death. Often, just a 3 or 4 artillery chain is enough to send an opposing magician to a quarter health or less for one final execution shot. Pick a target and keep them locked on.
Making Good Impressions
The Barrage Limit has been mentioned several times in this guide, so now is the time to learn how to increase it.
Keep note that the Barrage Limit is not an upper limit on how many times you should shoot in a fight, but a general guide on how to maximize your consistent damage. As you play Kog more, the Barrage Limit starts to become more instinctual.
Barrage Limit starts at 0 and increases depending:
Raj of Barrage
There are times when it's time to stop holding back and go past the barrage limit. Blow out a full 10-ult barrage and cripple opponents... and yourself.
Realize that pushing past the barrage limit too much will make you useless for any further fighting. As such, it makes sense that the barrage limit should only be exceeded when something can be secured or defended.
That can mean a several things including but not limited to:
- Securing a kill
- Securing an objective
- Securing a kill to secure an objective
- Defending a turret from low-health opponents
- Keeping a small area scouted while taking a ward
- Taking blue buff quickly, since the mana will regenerate
- Holding off opponents from defending an objective when it is almost dead
- Stopping a baron/dragon attempt; remember that baron shreds magic resist!
- Rushing a baron/dragon where your team plans to peace out after securing it
May your acid reign be endless.