Dr. Mundo Build
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.
It's been said before that Mundo is a g*d d*mn Mack Truck. Metaphorically speaking, this is true. Not only is he capable of taking hits, he can push down a lane like no one's business AND do some decent damage along the way.
This is a high dps tank build. In fact, I would say it's Mundo's natural build. I'm not going to touch rune itemization, because TBH it doesn't really matter. Use whatever runes you like.
First and foremost Mundo craves move speed. Why does Mundo like move speed? To get him in to position quick enough to fire off his cleavers, of course... which brings me to an important point... The key to this build is to constantly be active. What I mean by this is constantly be harassing the enemy AND getting last hits. Mundo likes money as much as he likes hurting things.
You'll want to max out infected cleaver asap. Your priority is this: Sadism, Cleaver, Masochism, Burning Agony. Or, once you get a Warmogs, immediately put one point into burning agony. It helps to rack up the kills.
This is where I explain why I take the items I do, in the order I have shown. The first item i always go with is boots. The extra move speed at level 1 makes it so much easier to do the get-in-cleaver-get-out rotation. Mundo's passive helps with health regen. Add a few health pots and you're good to go. No, you don't NEED Doran's Shield AT ALL.
My first blue pill brings the biggest decision. If I'm doing "very well" to "alright" then I'll pick up Boots of Swiftness. If I'm getting harassed more than I'm harassing or if I got ganked early, I make a bee line straight to Spirit Visage.
However, I'm usually doing pretty well early game. But it is easy to get into the mindset that Mundo is invincible and start doing stupid things like overextending and towerdiving too early.
The second major decision is whether or not to get Warmogs back to back or stick Atma's Impaler between them. Again, this depends on how I'm doing in the mid game. If I'm completely creaming them, I take Atma's Impaler immediately. If I've had a few deaths or am not doing very well, I take the second Warmog's.
Those are really your only major decisions. Otherwise, just follow the build order. By the time you hit 18 you should have Boots of Swiftness, Spirit Visage, Warmog x2 and Atma's Impaler. If you've been charging up Warmog's you will have around 5200 health. The passive on Atma's will turn that health into 100+ attack damage. I usually have around 200-215 total attack damage before masochism. Depending on where you sit, health wise, you should get an additional 100-180 attack damage when masochism is active. (I try to stay at about 50% health at all times for the added bonus.)
At this stage, you should have yourself a bonafide MUNDOTRUCK rolling around. Sadism will make you practically invincible but you aren't doing a tremendous amount of damage... yet. Add on Phantom Dancer and Infinity Edge. Watch your max attack damage go to around 450. With ~75% critical chance, most of your melee attacks should be hitting for upwards of 850.
Now it's time to fill three distinct roles: Tank, DPS and Carry. On many occasions, I have charged a full lane, blasted straight past the higher hp units to the squishies, scored a kill and retreated back with sadism ticking away and full health. Yes, you can dive a full team hugging a tower, score a kill and get away with practically full health with this build.
Early game: pick a lane and a partner and STAY THERE as long as you can. The key is to get Sadism as quick as possible to keep you in the lane, last hitting things and harassing the enemy. Remember that Mundo is a Mack Truck, so he can take a few hits... just don't be stupid. The only time I break this rule is if I get to below 15% health. Early ganks and deaths will hurt you more than you might think.
P.S. Mundo is MORE than capable of soloing mid, despite what people may think. If there is not someone much more suited to it (read: Teemo and a few others) you should consider vying for the mid spot. Against most toons, mundo is very capabale of pushing them off the XP line and harassing enough to make them mad or careless. (Or both.)
Mid game: Around level 9 you may want to consider jungling a bit, so long as you are not competing with another team member. Get your dual Warmogs asap. One you get Atma's Impaler, it's pretty much game over for the opposition. Nothing like 4500+ hp and over 300 attack damage with Masochism going.
Late Game: If you haven't won by now, start stacking crit. I love watching 600-700 melee crits ravage my opponents. Let the Mundo Mack Truck do his thing. Remember that Mundo really likes helping his teammates, and with his final speed he's easily capable of ganking on the other lanes.
A note on summoner spells:
While others may claim that Mundo MUST have cleanse, I tend to disagree. Burning agony helps a ton with reducing slow times. Mundo MUST have exhaust. It's the only way he's able to half *** fill the tank spot. And, while I prefer ghost, you may want to replace it with Teleport or even Flash.
Built correctly, Mundo can have the best of both worlds... tons of hit points AND damage. Atma's Impaler is obviously the star of this show, but don't discredit the late game power of crit stacking. Feel free to charge your enemies and lead your team to wreaking havoc!