DISCLAIMER: THIS IS NOT AN IN-DEPTH RAMMUS BUILD AND THE IDEA IS MADE IN A (semi-) TROLL GAME!

Hello Moba,
This is my third build and my English is not the best IMO so I think their will be some grammar mistakes and... Wait? What?! Are u serious AP Rammus? Yes I'm very serious. OMG noob why AP go full tank. Did you see that amazing AP ratio on Powerball? 100%!!!
Now let's get this build started, and I will explain why Rammus is so ****ing amazing on AP!

*Note: IMO this build is at it's best in 3v3, especialy with premades
*Note2: This is not the best for high ELO play or stuff, but it's IMO very fun.
*Note3: If you say ' Rammus needs alot of armor OMG' I reccomend trying the Off-Tank Build.

Ravaged by Rune Wars long past, the lands south of the Great Barrier are wrecked by chaotic magical storms, leaving the grasp of nature's rule tenuous at best. While abnormal flora or fauna are the norm rather than the exception in these ruined areas, perhaps none is more curious than the case of Rammus. While no one is entirely certain why an armadillo from the Shurima Desert crossed the ***ungu Jungle into the Plague Jungles, Rammus made just such a journey. There, amongst the twisted vines and festering rot, he came across an oddity - a healthy evergreen hedge maze, stretching as far as the eye could see. As he explored the maze, something compelled him toward its center - a light, a presence of some kind. As he drew closer, the light surged, blinding him and knocking him unconscious.

When he awoke, Rammus' whole world had changed. The maze had vanished and he felt truly cognizant for the first time in his otherwise unremarkable life. As his predicament dawned on him, Rammus had a moment of panic. As he trembled, the earth around him began to shake, the intensity increasing until he managed to steady himself. As the quake receded, Rammus arose and left the Plague Jungles in search of others like him. His search brought him across all the lands south of the Great Barrier, but everywhere he went, he was unique. The hardships of this sojourn inspired him to craft the suit of armor that would earn him the title of Armordillo. Rammus' quest eventually drew him to the only place where a sentient armadillo is less than confounding - the League of Legends.

''I've seen a lot of things, but this... this is a first.'' - Ezreal, the Prodigal Explorer, after first meeting Rammus

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Pros: + Massive dmg with Powerball and Soaring Slam + Can save people's ***es many times + Strong chasing power + Has awesome 'quote's' + Defensive Ball Curl will give you great defence + Easy to play + Blitz has nothing on you!

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Cons: - Not as tanky as full tank Rammus - Hard to master - AP Rammus will eat mana when played to spammy - Ranged stuns, snares or strong slows will make it harder to hit Powerball

Greater Mark of Magic Penetration: Since your dmg as AP Rammus is mostly magic, MP is a good thing to have
Greater Seal of Health: With an extra 48 HP at lvl 1 you will be alot tankier then others.
Greater Glyph of Ability Power: That AP in the early will make your Powerball a feared tool of destruction.
Greater Quintessence of Health: Same story as Seals
Greater Quintessence of Ability Power: Same as Glyphs

Alternatives:
Greater Mark of Health: If you want a more tankier build get these
Greater Seal of Armor: Armor will benefit your Defensive Ball Curl and it makes you tankier ofc.
Greater Glyph of Scaling Ability Power: This beats the flat AP Glyphs on lvl 8.
Greater Glyph of Magic Resist: MR is always nice.
Greater Glyph of Scaling Magic Resist: These runes give a nice amount of MR in the late-game

Full AP:Tanky AP:Sustained-Tank:

Sequence:
Q>E>W>R
You want to suprise someone with Powerball and let him feel the power of AP Rammus with your combo chain (E>W>R). It's even better to stay in a bush and wait when they come close. Max your Q for more damage, or make a combination between W and E and max Q last if you're the only hard CC champ in your team.

Explenation:

Passive= Spiked Shell: When I play Tank- Rammus I ****ing love this because of this, the best defense is the best offense, but if you're planning to get alot of AP instead of armor, this passive will be somewhat... useless :P

Q= Powerball: Press Q to become the ultimate ball of speedy d00m! Gaining massive speed over the duration? **** YEAH!!! 100% AP ratio? **** YEAH!!!
Knocking back everything you hit? **** YEAH!!! a 40% slow that last for 3 seconds? It has many uses too:
- Just to get around
- Escaping
- Saving allies
- Interrupting channeled spells like Absolute Zero, Nether Grasp etc.
- Detect a stealthed enemy champion
- Initiate
- Chasing someone
- To one-hit creep waves (only possible when Powerball is maxed and you have above the 300 AP)

Riot plz don't nerf this :P Tip: Don't try to engage with Powerball when you see an enemy creep wave walking without attacking something, cuz they will run up to you and stop Powerball.

W= Defensive Ball Curl: Press W for temporary immortality! Not much to say about this, temporary AD bonus by your passive, thornmail like effect & massive armor and MR boost. Nuff said.

E= Puncturing Taunt: U want to kill my team enemy fed Tryndamere? TOO BAD!!! I just use this and my W to get yourself killed >:D This is on of the strongest CC spells in the game, 3 seconds taunt and the 30 armor reduction will give the non-armor enemies 0 armor :D

R= Soaring Slam: Press R to see enemy towers and champions, disapear! A really nice ultimate, not the strongest, but not a weak one. Combined with a proper amount of AP, you will deal some serious damage. Because Soaring Slam does do dmg against towers, Rammus can push very good, especialy when AP. Tip: Don't ult when you're pushing, and there are enemy champions near, because you will get turret aggro.

YEAH!!!:
Flash: Really amazing, especialy when combined with Powerball.
Exhaust: Now you're really mad aren't you Tryndamere?
Ignite: Nice amount of dmg in the early game, and the 50% healing reduction is a nice asset too.
Heal: U mad tower diving enemy?

Meh:
Ghost: Good, but powerball gives enough MS and Flash is much better, but, hell it's ****ing funny to see that MS xD
Cleanse: Pretty nice, but not that much of a fan of this.
Surge: Somewhat good, but the AS is a bit wasted.
Clarity: You're a mana eater, and when you got another mana eater as a teammate, maybe consider this.

What did you smoke...?:
Clairvoyance: Just buy wards if you want vision in 3v3, but it's not 'that' bad.
Promote: useless in the early, saw many games where a team lost because pushing too early in 3v3s.
Revive: ****ING USELESS IN 3V3!!!

Starting Items:

Doran's Ring: A very good choice for AP Rammus, HP, AP and some MP5.
Doran's Shield: Nice stats for a tank, but you will lack damage.
Regrowth Pendant+1x : Nice sustain. Nuff said.
Boots+2x +1x : Nice MS and sustain in the early.

Boots:
Sorcerer's Shoes: You go AP so...
Mercury's Treads: Get it when you see they have a strong caster, and alot of CC
Ninja Tabi: When the enemy only has little CC and has more AD dmg then AP dmg, get these.
Boots of Swiftness: + Powerball+ Ghost= :D

Optional Items:
Rabadon's Deathcap: AP :D
Rod of Ages: Good all-around stats, and has good passives. It's wise to get this early.
Rylai's Crystal Scepter: A really great item. A chunk of HP and AP, and what's really great is the passive, Soaring Slam will be a strong chasing tool, and Powerball slows even more.
Will of the Ancients: An good aura that benefits your team, and spellvamp is very good on Rammus. You ask me why? Your Q, W, R will give you nice amounts of HP back. And I find it funny to see that I'm almost not dmged when my W is on.
Athene's Unholy Grail: Hey you! Yes you there! I heard you got some... mana problems... you wanna fix it? Yes? Good, I got here a little item here that will fix it... You can have it for let's say... 2950G. Oh and it will give you something back too when you kill some people.
Zhonya's Hourglass: Armor and AP, that's what Rammus needs! I once made a double 1v3 with this, Powerball in, then E>W, but when I was close to death, I ulted and popped this badboy on, and said in chat: U mad?
Abyssal Mask: Buy it when the enemy team has a majority of magic damage, and when they cower in fear and start buying MR.
Guardian Angel: A nice amount of armor and MR and the passive will give you a second change and use Powerball to get away :D (this works only when the enemy team is low on HP or is just too dumb to think about surrounding you so you can't Q yourself to safety).
Aegis of the Legion: Nice defence in the early game, and the 8 AD will benefit your team so good :D
Warmog's Armor: HP. Nuff said.
Mejai's Soulstealer: You will most of the time escape, but better pick it when you're more then 3 kills in advantage.
Thornmail: Ooh, now you're really mad aren't you Tryn
Randuin's Omen: See Thornmail explenation
Frozen Heart: See Thornmail explenation
Banshee's Veil: Looks cool when you're Powerballing, oh and it blocks spells too.
Lich Bane: Only get it when you got a solid amount of AP.
Haunting Guise: When thing get bad for you, this will help alot.
Deathfire Grasp: Gives you a ranged spell with it very strong, and a nice amount CD and AP.
Morello's Evil Tome: Nice stats, but the most of the time I get this when I'm against a fed Dr. Mundo or Vladimir.

This is very easy to understand. Just Powerball in, and taunt the AD that does the most dmg, but, if there is a really fed Annie for example, it's best to taunt her, so your teammates can kill her without getting dmged by her. When you taunt someone, don't forgot to turn W and your ult on, for maximum dmg output.

So... Don't like the altar thingies, but it's actually a good thing for Rammus. AP Rammus can easily defend both altars from any lane with his insane mobility and dmg. I found out that movement speed increases are OP in the new TT, since blinks and Flash are almost useles since you can't jump over walls. And with the incoming buffs for Rammus, AP Rammus will be OP as he never was!

Hope you all like this and give me some feedback, and btw: RAMMUS TAUNTS EVERYONE!!!
Play Video
Taunts:
Akali: Quit gettin fed, fatty.
Alistar: Olé
Amumu: QQ
Anivia: I'ma microwave your drumsticks.
Annie: I'll show you crowd control.
Ashe: Dat Ashe!
Blitzcrank: Grab me! C'mon, grab me!
Brand: I'm gonna make some S'mores on your face.
Caitlyn: You couldnt hit the broad side of my ***.
Casseopiea: Tasty, tasty venom.
Cho'gath: You, sir, are a ruffian and a scoundrel.
Corki: Whisky Tango Foxtrot is comin' out of your face?
Doctor Mundo: Looks like Mundo goes where I please.
Evelynn: I got 400 gold that says you're worthless.
Ezreal: Ain't you just precious.
Fiddlesticks: If only you had a brain.
Fizz: Go back to your themepark, Disney.
Galio: Xanatos called, he wants his ***** back.
Gangplank: I wouldnt let you captain a dinghy.
Garen: Oh look, a merry-go-round.
Gragas: I want a pony for Christmas.
Graves: Go break your back on a mountain.
Heimerdinger: Go build yourself a hugbox.
Irelia: What are you, 15?
Janna: I'm gonna stick you in a window and cool my house.
Jarvan IV: Princess Jarvan wanna play dress-up?
Jax: Real weapon wouldnt help.
Karma: Yeah. Wait. Who are you again?
Karthus: Sing me a lullaby?
Kassadin: Your void is showing.
Katarina: Was that your ult, or were you have a seizure?
Kayle: Your sister's hotter.
Kennen: Wait, you're one of those Pokemons, aren'tcha?
Kog'Maw: I'll give you something to chew on.
LeBlanc: Hey, try that decoy thing again, maybe I'll fall for it this time.
Lee Sin: Heh. Never saw it coming.
Leona: Guess who brought shades?
Lux: I'mma Shoop Da Whoop your ***.
Malphite: I can stop the rock.
Malzahar: Quit puking on people.
Maokai: I hate hippies.
Master Yi: GET DUNKED. GET DUNKED. GET DUNKED.
Miss Fortune: Skank.
Mordekaiser: BRBRBRBRHEHUEHUEHUE
Morgana: Your sister's hotter.
Nasus: Who's a good puppy? Yes you are!
Nidalee: Cub looking for cougar.
Nocturne: Just call me Bill Murray.
Nunu: I hope you weren't planning on ulting. Ever.
Olaf: Shouldn't you be yelling at dragons?
Orianna: Must. Not. Make. Portal. Joke.
Pantheon:Your profession? Dead guy.
Poppy: Heh. Poopy.
Rammus: Do you really need this one written out?
Renekton: You're gonna make a nice pair of shoes.
Riven: You forgot your bunny suit.
Rumble: Don't make me climb up there to beat your ***.
Ryze: Spam harder, maybe it'll hurt.
Shaco: You're not Mark Hamill.
Shen: Ninjas don't kill people. I do.
Shyvana: Shyvana, The Half-***ed Title.
Singed: Please fling me into your team.
Sion: C'mere, Stinky.
Sivir: What do you do again?
Skarner: FEEL MY apathy.
Sona: Booobieees.
Soraka: Always, I want to be with you...
Swain: I'm gonna break that cane over your beak.
Talon: Original character; do not steal.
Taric: No comment.
Teemo: I hate you so much.
Tristana: Everyone does your job better. EVERYONE.
Trundle: I'll show you trolling.
Tryndamere: Heh. You mad.
Twisted Fate: Deuces.
Twitch: Here mousy, mousy, mousy.
Udyr: I'm gonna teach you my ***-whipping stance.
Urgot: I'm gonna roll you into a ditch.
Vayne: Twi-Hard.
Veigar: Oh no, who will save us from the Ebil?
Volibear: Someone gave up trying to name you halfway through.
Vladimir: That's not how you eat ice cream.
Warwick: Sit. Stay. Good boy.
Wukong: Monkey want a banana?
Xerath: I love it when they sit still.
Xin Zhao: I bet you miss being good.
Yorick: What's your name again?
Zilean: I'm gonna give you 1.21 *** beatings.