This guide deserves more upvotes IMHO :),but there is a problem: if you miss your q you miss tons of damage,as well if you hit it you deal tons of damage so that is depending on how good the player can skillshot.Conclusion:A very fun way to play him (very offensive) +1! :)

good!!!

Thx for the advice, i will change the runes but im with vetie on the sorc shoes, i will add it in as situational items but honestly i dont think sorc shoes will be very helpful. I would rather have mercury's even though sometimes i get boots of swiftness.

Also i did add abyssel scepter as a situational item. I added in force of nature because of the magic resist and because of the extreme regen, you have more than 3000 hp and you get 0.35% regen. This helps you get magic resist and regen. Which abysel scepter is reall the same thing except that instead or regen you get about 90 ability power. (70 plus 20). As i said in the guide some people would like to switch force of nature with abyssel scypter and im fine with that.

You can jungle with this build, this build is not a jungle build (no smite) and cd would on be used for your bandage and ult as psiguard mentioned so i dont think wasting money and a slot would be a good choice.

Dude you dont need sorc shoes mpen in mark/quint abyssal an dpassice . M res counts BEFORE mpen.

Meaning your passive reduces
35 magic res(will get shquishies to -5 early/mid)
+ Abyssal -20
Equals - 55 If they get banshees(wich is all a shquishy will get some times) they will have about 25 mres left. not much.

So the mpen from sorc 20 and quint/mark 32 will be wasted on many.

And you will be even less tanky wich is a dumb thing. Abyssal is good. but sorc shoes and mpen is situational. Dealing dmg to high mr targets(tanks/offtanks) isnt that important as squishies. if you get sorc shoes /mpen runes then only get abyssal if they have lots of mr i would say

I think if you're building an offensive Amumu (which I approve of, Amumu does a lot of magic damage), I really think you ought to have Marks of Insight. You have zero mPen in your items, runes and masteries, so even a champion's base magic resist is going to seriously gimp your damage output. Amumu's mRes reduction passive will help, but I would highly recommend investing in more magic penetration. Switch the marks to mPen, and possibly the quintessences as well, as you have a great deal of magic resist from your build and masteries already. Another option would be flat health quintessences, which are good on any champion. Also, you may want to consider replacing Force of Nature with Abyssal scepter, as both of them will give a decent amount of magic resist, but the scepter is another source of Ability Power and magic penetration.

One last suggestion: Sorcerer's shoes would make a great addition to your build if you think you can deal with the enemy team's CC. Between sorc shoes, abyssal scepter, and amumu's passive, your magic penetration will jump to 75. That's a much more respectable number, allowing you to punch through tanky opponents' defenses with your abilities, while sacrificing very little in terms of survivability. Add mPen marks to that, and you'll take down Cho'Gaths just by crying near them. :)

Anyway, hope some of that was helpful. Keep improving your build, AP amumu is very viable and is a surprisingly tough caster that I don't see very often.

Oh, and in regards to Vetle158, Amumu really doesn't need CDR as much as other casters. You only need your Bandage Toss to initiate and your ult to net kills, while your aura is on like a .5 second cooldown and the cd on Tantrum is reduced with every hit you take. If you really wanted CDR though, Glyphs of Celerity would fit in relatively easily, as the flat ability power can easily be removed in favour of a stronger late game.

Much better :)
really like it.

Only problem is that you have no cdr.. would be hard to itemize for i think but it could be usefull..
Aaand can i jungle with this?

sry vetie i accidently published without anything. It is now fixed i hope you take time to read it again :D

i miss An item section

A gameplay section?
Tips section?
Runes?
Skill sequense section?
Optional items?

Can i jungle with the build?

Interesting but it really lacks... almost lacks so much i down voted... fix these things and i will probably up vote