Not Updated For Current Season
The masteries shown here are not yet updated for the current season, the guide author needs to set up the new masteries. As such, they will be different than the masteries you see in-game.
Okay first thing is that in the items there are 7 items. Before you give me thumbs down for being a "can't count ******" I realise this and I know this makes the stats null and void. But it's because you choose between will of the ancients and abysal sceptre. However, tehre are a lot of mistakes on mobafire regarding items and runes (even the mana per level runes I have noticed are wrong it actually totals at 58)
I have been playing amumu for months and this guide has evolved to what I find best. The amount of AP hybrid is optional, but the tank factor is certainly necessary.
Amumu is an excellent tank and tank buster in my own opinion given the right laning mates the best in a team fight. He is also extremely fun to play,. You may not get many kills but assists should be through the roof.
Amumu's most effective place to launch his ult is within range of all 5 members of the enemy team often making himself their first target. When you have say 3 or 4 enemies in your ult snared, and up to 5 are attacking you coz let's face it you probably won't get all of them you're going to be a likely target. So you need to tank.
Apart from a Blitzcrank pull and Ashe with an arrow, Amumu will and should always be the one to initiate a team fight.
Let's start with summoner skills.
Exhaust: Amumu's skills are very short range, so once you've bandage wrapped in you want to keep them in Despair's range of effect and tantrum's. If you're going in for the kill it really stops them going away.
Fortify: I take this all the time because any escape mechanism (ghost flash cleanse are wasted coz Amumu so often dies from diving in with his bandage warp and ulti where you don't run away so best to keep this to keep towers alive.
Bar two items, it's pure tank build.
You may have noticed the items are very expensive. You will very rarely get all of them, unless you are getting a lot of kills and doing lots of farming in a very long game. This build isn't set in stone. It gives a nice balance between magic resist armour and health, with some AP oomph.
For this to work you need the items marked with a star (*).
Sunfire cape* : After boots this is your first item. It is absolutely necessary for farming otherwise you need to use up valuable team fight mana from despair killing creep waves.
Force of Nature*: Standard magic resist item.
Rylai's *: This gives you health, so still tankin, and gives you a lot of kick.
Mercury Treads: Nice magic resist and reduces disasbles and slows on you which is nice. Obviously you have to tank what they throw at you so if their main damage dealer is AD rather than AP then go ninja tabi. If the enemy aren't that good and aren't putting enough pressure on you to keep in lane go for the fastest boots you can afford for ganking and chasing them down.
Will of the ancients / Abysal Sceptre: If you have two or more AoE mages esp. Ryze or anivia take will of the ancients. If not take Abysal Sceptre for the magic resist and lowering magic resistant passive which stacks with Amumu's personal passive.
Randurin's Omen: This is a great item. The cooldown reduction, armour and passive make it amazing. Turn the active on just before your ult wears off. Admittedly without a taunt the 20% chance to slow upon hitting amumu isn't as effective as on shen or Rammus but this is certainly a great item and gives a lot for its cost.
Other items you can consider are:
[*] Banshee's Veil- if you are getting stunned a lot and are struggling with a disable heavy team. The magic resist is also nice.
[*]Thornmail- If they have a madman yi or someone like that on the loose this is an amazing piece of armour.
Remember these items are really dependent on the situation.
Runes and masteries:
[*]Magic resist and cooldown. Amumu doesn't get much magic resist so it's good to give to him.
[*]I have gone for utility and attack. They complement my summoner skills.
Due to amumu's passive any high damage magic champion works well with you in lane. Ryze and zilean are quite effective. Another good one is Nasus. When you both have ults you can double kill most champions. If you do get Nasus as a tank on your team, the perfect solo mid is Anivia for the AoE ult because she can spam it. Fiddlesticks is also very good but it requires much more coordination.
During the champion select decide how confident you are against their team. If confident go for boots and health and mana potions. If not confident go for doran's shield and mana potion. At level 4 it may be possible to jungle a bit. It usually pays for you to be aggressive but this depends on your lane mate.
I love to play aggressively with Amumu.
You should be keeping an eye on turrets for fortify. Keep farming as much as possible and look out for ganking oppurtunities. It is probably best that you be the first line of defense against a push on a lane. If there is a team fight imminent you should always be there and should initiate with your ult. Amumu should be the most aggressive tank, the only exceptions are a fed Chogath and possibly a Rammus.
Keep with your team mates and keep looking for a chance to pop your ult. If you're defending, place sight wards around your base so you can bandage wrap through walls to get to people hiding outside alone. If you're winning just be there for your team. If you are winning it's likely you'll pop your ult help your team get the kills take out the inhibitor and realise you're on low health and mana and have to run back.