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Cassiopeia Build Guide by GP Finn

AP Carry Cassiopeia Mid Lane - Season 5 (In depth)

AP Carry Cassiopeia Mid Lane - Season 5 (In depth)

Updated on May 19, 2015
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League of Legends Build Guide Author GP Finn Build Guide By GP Finn 175,233 Views 9 Comments
175,233 Views 9 Comments League of Legends Build Guide Author GP Finn Cassiopeia Build Guide By GP Finn Updated on May 19, 2015
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LoL Summoner Spell: Ignite


LoL Summoner Spell: Flash


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Middle Lane
Ranked #24 in
Middle Lane
Win 51%
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Middle Lane Ranked #24 in
Middle Lane
Win 51%
More Cassiopeia Runes

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Hello valued reader! My name is Henry (aka GP Finn) and today I will be showing you how I play one of my favorite mid-laners: Cassiopeia.

Just a little bit about me...
I am the mid-laner for Team GP and have a large champion pool that includes Ahri, Nidalee and Fizz among others. I am pretty new to league (started at the end of season 4) but below is a link to a few highlights from a game just to show my level of play.

Anyway, I was turned on to Cassiopeia when I was looking at win rates and pick rates of mid-laners and saw that Cassiopeia was near the bottom of the most played champs. I like to play under-used champions and so I decided to give her a try and oh lord did I love her. I loved how she played and I began to get good with her until she became one of my mains. Her kit is fantastic and she has been buffed twice as of the beginning of season 5 so she is an extremely viable option.

So I hope you enjoy this guide and I hope you learn something from it to either begin playing Cass or change how you play her and hopefully improve.
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Pros / Cons

- Great Carry Ability
- Consistent Damage
- Game Changing Ult
- Great 1v1 and in Teamfights
- Lane Bully
- High Skill Cap
- Very Strong as of Beginning of Season 5
- Fun to Play

- Hard to Master
- Not Much Escape
- Missed Ult in Teamfight = ace
- Bad if Behind
- No Massive Waveclear
- Have to Hit Poison to do Much Damage
- No amazing skins :(
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These runes let us have some good early AP do get some great early harass in lane and get a big cs lead over our opponent. The magic penetration is also a must for mages and the defense negates early auto attack harass.
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Quite simply our masteries are aimed at AP, mana regeneration and a little bit of health to keep with the theme of a high AP mid laner who isn't too squishy.
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This is going to be a long section so if you want to skip to gameplay then just scroll past all of this. For those of you who want to know about my item choices, this section will detail each item and how it fits with Cassiopeia.

Starting Items

These are pretty basic as Doran's Ring is the classic start for mages with the AP, mana regeneration and health. Health Potion is necessary for sustain early game and always get trinkets! Boots are an option for someone with tones of skill shots you need to dodge like Ziggs. Sapphire Crystal is kind of an unusual start but you can use it to get an early Tear of the Goddess and start getting stacks.

First Back

You need to grab your Tear of the Goddess as you need it to start spamming your spells and getting stacks to increase your mana pool. This item works great on Cassiopeia because you'll be spamming your Noxious Blast and Twin Fang a lot in lane to bully and last hit minions so you can get a ton of stacks in a hurry.

I always try to get a quick Blasting Wand after my tear to get some early AP to keep up my harass and not fall behind. It can build into several of our final items so an early one is always good.

If you didn't grab Boots to start then getting them early is also a must. Cassiopeia is slow and needs some movement speed to stay safe in mid so grab the basic boots now and upgrade later to Sorcerer's Shoes.

You can alternatively buy Ionian Boots of Lucidity for the extra cool down reduction but you'll have to grab Void Staff later to have your magic penetration.


These are the items you should be getting almost every game. You can always switch out any item you feel would be better but these items work really well on Cassiopeia and give us a snake that can carry any game.

Seraph's Embrace is one of the key parts of this build. This build gives a lot of mana and the passive on Seraph's Embrace gives you extra AP based on your mana. The item also comes from Tear of the Goddess and while this is a key piece of our build, don't build Tear of the Goddess into Archangel's Staff until you have the full stacks on it and get all the bonus mana. Plus the shield from the active is always nice to have before engaging a fight.

Rabadon's Deathcap is another key item for all mages who want a huge AP spike. The 120 AP is huge and then the 30% AP increase is just like our passive at full stacks (I'll talk more about that later) but this essentially gives us a 60% increase in AP late in the game.

Will of the Ancients is another item that works extremely well with Cassiopeia's passive. Her passive grants her spell vamp with her Twin Fang at a certain number of stacks and with the extra 20% spell vamp from Will of the Ancients, you can spam Twin Fang against champs for some great dueling potential or use it to farm minions for some good recovery and sustain. The AP and cool down reduction are also great. (More on this item later)

Rylai's Crystal Scepter is the final part of our core and is Cassiopeia's main item because of the slow. You can chase people down really easily with that slow and the health makes us less squishy.

In terms of a build order, I like to start with an early Hextech Revolver to get some early spellvamp and get ready for my Will of the Ancients. Now comes a choice. You can either hold off on finishing Will of the Ancients for a bit and start working on your Rylai's Crystal Scepter or you can just finish the Will of the Ancients and get more spellvamp and cooldown reduction.
After those two are complete you should be looking to build Zhonya's Hourglass or Rabadon's Deathcap or even look at finishing your Seraph's Embrace if you have full stacks on your Tear of the Goddess.

Other Offensive Options

Many of you might be wondering why I left Zhonya's Hourglass off my core build. Don't get me wrong, it is a damn good item on almost all mages and you should try to get it almost every game. My reason for not having it in my core is it shouldn't be your first priority. But regardless, I still get it as my 4th or 5th item every game.

Morellonomicon is a good item with the cool down reduction and AP plus the passive sets up some easier kills as well. Overall a good item but not something I take super often.

Like I said earlier, Void Staff is a good item especially if the enemy team is stacking magic resist. This something I buy late game if I'm satisfied with my AP and I didn't take Sorcerer's Shoes. I've topped 900 AP multiple times without my full build so while the magic penetration certainly helps, I'd rather build a defensive item at that point to stay alive. You can have all the AP and magic penetration in the world but if the enemy team focus you first every time, you can't do much with it.

____________________________________________________________________________________________ Defensive Items

I try to take at least one of these every game unless I'm doing really well and just want a ton of AP.

Banshee's Veil is my item of choice against a team with lots of AP (or if they have a Veigar). The shield is great for negating a really tough spell and the HP is great to stay tanky.

Guardian Angel is something I buy if I'm doing well. The armor and magic resist help stay tanky and then the passive lets me keep my kill streaks going and not get shut down. Also, it's a great feeling when the other team focuses you and blows some ults and then you come back to life and wreck them ;).

Rod of Ages is something you can buy in any game and feel good about it. You get a little more meat on your bones and some more mana to go with your Seraph's Embrace passive. If you're going to build it though you have to build it early to start gaining stacks.

Abyssal Mask and Athene's Unholy Grail are both items that you can build against AP team compositions. I always grab Abyssal Mask against Katarina and other close range AP champs.

Full Build

The exact final build you use comes down to how the game is progressing, the enemy team composition and personal preference but this is the build that seems to work the best for me.

Seraph's Embrace a fantastic item on Cassiopeia that you should always aim to get. Spamming Twin Fang and Noxious Blast will use up a ton of mana so the huge amounts of mana you get from this item plus the extra AP you'll get from the Seraph's Embrace passive make this an item you need to have every game.

Will of the Ancients and Rabadon's Deathcap are the other two items that you should aim for every game as they give you some great spell vamp and cool down reduction and a massive AP spike respectively.

Sorcerer's Shoes are a must for a mage as you need that movement speed and the magic penetration for late game. You can, however, get Ionian Boots of Lucidity for cooldown reduction and just buy Void Staff later for the magic pen. I like to take furor because of the single target effect and it can be spammed with Twin Fang. You can always grab homeuards instead if you're behind or just wanna be super fast for a few seconds.

The last items really comes down to how you're doing and how tanky you feel like being. If you want more AP and health then take Rylai's Crystal Scepter as your final item. If you want magic resist then Banshee's Veil is gonna be what you want to get. Out of everything I recommend Zhonya's Hourglass or Rylai's Crystal Scepter as your final item after the core and the boots. You can also grab Rod of Ages for a great for an all around item.
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Justifying Will of the Ancients

Will of the Ancients is a somewhat controversial item on Cassiopeia but I think it is an item you need to buy every game. There have been countless times where someone has tried to all-in me and I just take some damage for a second before I turn around and ult them then lay down some poison and spam Twin Fang and with that spellvamp plus my passive I can destroy people and sustain myself well in any 1v1.
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Skill Sequence

This is the part where I'll explain how each of Cassiopeia's spells work and how to use them correctly and how our items work with them.

Passive: Aspect of the Serpent
Holy cow this passive. It's one of the best in the game in my opinion for mages and here's why. You gain 1 stack every 6 seconds (so 10 stacks per minute) and 1 stack for every second an enemy champion is poisoned by Noxious Blast or Miasma.
- At 100 stacks, you gain 5% bonus AP and Twin Fang starts to heal you for a percentage of damage dealt
- At 250 stacks, you get 10% boosted AP and 25% cool down reduction which is pretty sweet.
- At 500 stacks... well now you start to get really scary. You get 30% AP boost plus everything you got before. So at 500 stacks your passive gives you a free Rabadon's Deathcap passive, spellvamp on your Twin Fang and some great cool down reduction. Like I said, one of the best passives in the game.

- Try to land as many poisons as possible on the enemy champion to get stacks quickly
- Once you hit 100 stacks, you can stay in lane for a lot longer because you get get health and mana back by last hitting minions

Q Noxious Blast
This is your primary poke too. It's automatically on smart cast (I'll talk about smart casting soon) and you can get some good poke whenever you opponent stands still to last hit. It does some pretty good damage but it is mainly a utility ability to set up Twin Fang spam.

- Whenever you see your opponent stand still to last hit a minion, try to land the poison on them
- Every time they get a little too close, try to land you poison so you can spam your Twin Fang and do tones of damage
- Never engage an enemy unless you land a poison, either Noxious Blast or Miasma.
- This ability has a pretty long range so use it for some safe harass
- You also get a speed boost by landing it successfully so use it to run away or catch up or check a bush (if you get a speed boost then you know you hit someone in the bush)

W Miasma
This is another utility ability to help poison the target for a Twin Fang spam. The thing that makes this one different is the fact that it does less damage and has a shorter range but slows the enemies that walk through it and the poison has the potential to last a while if they stand in it.
I usually only use this if I miss my Noxious Blast or if I need to escape. It's also good for when someone all-in's you so you can drop this at your feet and spam Twin Fang forever.
This has a much longer cool down than Noxious Blast so don't use it to harass as much.

- Use the slow to get away or catch up
- Because of the short range, use it as your close range poison or to help last hit minions
- Use this for protection if someone all-in's you or if you land your ult
- The slow from this plus your speed boost from Noxious Blast will let you escape a chase pretty well

E Twin Fang
Your entire kit revolves around this one ability. This is how you do everything as Cassiopeia. This is your harass, your sustain, your main damage source, you assassination, your everything. At first glance it just seems like a pretty good ability with mediocre AP ratios. But when you factor in the fact that you can hit your enemy with FOUR of them every time they get poisoned... the amount of damage you can do is incredible.
You can end up using a lot of mana by spamming this ability but with our build, you won't really have to worry about mana very much, especially after we get a few core items.

- Never use Twin Fang on a non-poisoned target unless you are last hitting a minion or getting a kill. It will go on full cool down (5 seconds) so for those 5 seconds you are left without your primary damage source and are essentially doomed if they decide to focus you
- Use it to harass in lane if you land a poison. You can essentially force your opponent to leave the lane and miss experience and farm
- Focus squishy targets in a team fight as Twin Fang will completely wreck them
- Once you shoot 3 Twin Fang, try to land another poison before spamming again so you can avoid having it go on full cool down
- Once you become more comfortable, you can try to land 4 Twin Fang if you poison them with Noxious Blast and even more if they are poisoned by Miasma, especially if they stand in it at all
- Don't be afraid to spam it!
- Make sure you put it on smartcast or you will never be able to do enough damage

R Petrifying Gaze
This is your game changing ult. You shoot our light from your eyes in a somewhat awkwardly shaped cone. If any enemies inside the cone are facing you, they are turned to stone and completely stunned for a couple seconds and if they have their backs to you, they are severely slowed.
This is a very powerful ultimate, especially in team fights. If you can ult even just two people on the other team in a teamfight, you should usually win it no problem. You can also ult someone if they go all in on you. It is some intense CC and lets you go immediately on the offensive.

- Don't waste this ult and risk missing it but also don't be afraid to use it
- You will miss some ults and people will probably laugh at you but once you get used to the range you will be very scary to the other team
- Ult in a teamfight when you can comfortably hit at least two enemies
- You can ult someone who is chasing you to escape pretty easily
- If someone like Katarina for example jumps on you and ults, just ult her right back and throw down a poison and then wreck her with Twin Fang

Cassiopeia is a champion that you NEED to use smartcast with. She was the champ that taught me how to smartcast and now I use it on everyone I play. For those of you who don't know, smartcasting is an option you can turn on in settings in game which allows you to use abilities simply by clicking the key on your keyboard and holding your mouse over your target. This is will make your casts more efficient and allow you to land sooooo many more Twin Fang and do so much more damage.
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For summoner spells I take Flash and Ignite because first of all everyone should take Flash for the escape or to secure kills. Ignite is great for securing kills to and stacks damage over time with your poisons that will deal a lot of damage even after your enemy runs away. Other acceptable summoner spells include Teleport if you want map presence, Heal if you are newer and want to stay in lane longer and Exhaust if you are bad at landing your poisons.
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Cassiopeia is not the best farmer in the world, especially early in the game. That being said, she has some great sustain once she gets 100 stacks on her passive with Twin Fang. If you kill a minion with Twin Fang, you get all the mana you used on it plus 3% of your total mana back. With the spellvamp from your passive and then eventually the spellvamp from Will of the Ancients, you can stay in lane forever in theory and farm to your heart's content.
One recommended strategy strategy for farming whole waves is to lay down a Miasma on the caster minions and then once they hit around half health use Twin Fang to clear them very quickly.
Also, if you escape a teamfight with low health, farm some minions with Twin Fang or a jungle camp to get your health back quickly.
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Like I said at the beginning, Cassiopeia is a very fun champ to play with tones of carry potential but she can be hard to master. If you're a new Cassiopeia player, play a few co-op vs. AI games to get used to her abilities and how to use them.

As for this build in particular, try to build a Tear of the Goddess first and then build two or three AP items like Rylai's Crystal Scepter and Will of the Ancients and save your tank item for last or second to last.

This build may take some getting used to and I cannot guarantee results right away but as someone who mains Cassiopeia, I think this build is one of the best for mid lane.

Thanks for reading this guide! Hopefully you learned something and please leave feedback! It really helps improve the guide and lets me know what you all think of the way I play Cassiopeia.

If you enjoyed the guide please let me know and vote this guide up!

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Here are a few videos of me playing, not just Cassiopeia but also my other mains like Nidalee, Ahri and Fizz. Check them out! :D

Cassiopeia Videos:

Other Champs:
League of Legends Build Guide Author GP Finn
GP Finn Cassiopeia Guide
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Cassiopeia Mid Lane - Season 5 (In depth)

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Teamfight Tactics Guide