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.
This is an Off Tanking guide to the champion Rumble, the Mechanized Menace. A little history behind this character....
Even amongst yordles, Rumble was always the runt of the litter. As such, he was used to being bullied. In order to survive, he had to be scrappier and more resourceful than his peers. He developed a quick temper and a reputation for getting even, no matter who crossed him. This made him something of a loner, but he didn't mind. He liked to tinker, preferring the company of gadgets, and he could usually be found rummaging through the junkyard. He showed great potential as a mechanic. His teachers recommended him for enrollment at the Yordle Academy of Science and Progress in Piltover, where he may very well have become one of Heimerdinger's esteemed proteges, but Rumble refused to go. He believed that Heimerdinger and his associates were "sellouts", trading superior yordle technology to humans for nothing more than a pat on the head while yordles remained the butt of their jokes.
When a group of human graduates from the Yordle Academy sailed to Bandle City to visit the place where their mentor was born and raised, Rumble couldn't resist the temptation to see them face-to-face (so to speak). He only intended to get a good look at the humans, but four hours and several choice words later, he returned home bruised and bloodied with an earful about how he was an embarrassment to "enlightened" yordles like Heimerdinger. The next morning he left Bandle City without a word, and wasn't seen again for months. When he returned, he was at the helm of a clanking, mechanized monstrosity. He marched it to the center of town amidst dumbfounded onlookers and there announced that he would join the League of Legends to show the world what yordle-tech was really capable of, without hiding behind a foreign banner.
Pros / Cons
Provides a Strong Role in a Team Fight
Strong Unit in End Game
You don't deal as much damage as other Damage Dealers
Weak in Early Game
You are a magic based character these rather speak for themselves. Between these 9 runes and Sorcerer's Shoes that's just about as much Armor Penetration as you are going to need to get through most people's resistance that don't build into Magic Resist.
Your early game harass and your contribution to a team fight all rely on how much you can get your moves out there. Since Rumble has a unique skill cost system all of his abilities are essentially free with proper planning. So lets get them to be spammed as much as possible with no cost to us!
Nice boost to your abilities in the early stages when everyone's stats are low. If you want to play this a little more defensively you might consider Greater Quintessence of Health or Greater Quintessence of Armor or Greater Quintessence of Magic Resist
There isn't much to say here, this is a pretty standard Magic Caster build with some "fluff" in the Utility tree just to get you to your 20 point final mastery, Preserverence and Utility Mastery being those fluff. The plus side to having Preserverence as a fluff, and yes I know I shouldn't be trying to condone Preserverence, is that you can take that point out of Spatial Accuracy and change it to Mystical Vision , if you have to take the Clairvoyance role, or Blink of an Eye if you would rather have Flash as your second summoner skill in stead of Teleport.
Such a great Summoner Spell, Helps with team fights to make the carry weak to provide more time to get the gank off on them. Helps with pursuing a fleeing enemy, and when you are ready to pounce on someone it's handy to have that little nerf to start the match off with a little extra edge. In my opinion a must have.
With the amount of slows you have in your arsenal, and the ability to dispense of minions very easily having you blinking around the map to provide help where it's needed is a great asset to the team. Early game gank on mid when they over extended too much, clean up a lane before it gets the chance to be pushed by the enemy team, or even teleporting to their base from a hidden ward for some nice back door action. You are a great harasser, share the love!
Another good option/alternative. Gets you around some minions so you can harass easily in the early game. Gets you out of trouble with the ability to hop a wall and boost away, if you were not warned of a gank coming your way. It also gets you away from annoying Champions like Anivia with here wall, or Karthus with his slow screen, or even Veigar's Stun circle.
Putting you down one less Summoner Spell to lend a hand on partial map vision really doesn't hurt you that much. Knowing if you are chasing someone as they lead you into a gank is very useful, or when your allies call out MIA's you can make a quick check to see if they are really just hiding out of Fog of War vision. As an off tank I feel that you are partially a support-ish role and this just lends that little bit more support your team could need. You aren't a main gank character so you don't need a Spell set like Exhaust and Flash/ Ghost, at least not for this build.
Your job in the fight is the deny the enemy mobility options, so this is why I suggest you go and get your feet done first.
You aren't very strong in the beginning of the game. I recommend getting some boots and 3 health potions to help you get away if your lane decides to both converge on you.
Next I suggest you go for Rylai's Crystal Scepter. It turns all of your attacks into a slow, which can be nice for little drive by's with your flamethrower and speed boost skills to save some friends. It also helps with your ganking power and harassment. On top of all of that it gives a nice health and Ability Power boost to make you more threatening in a fight.
This next part is really situational, depending on what you are up against. I still recommend the next to items but the order is based on if you are fighting more AD or AP champions.
VS. AD Heavy Champions
VS. AP Heavy Champions
I choose to go with Frozen Heart over Thornmail because with it, you max out on your Cool Down Reduction, and slow everyone around you in Attack Speed. Which will lend a nice bonus to your allies when in team fights. You only lose 1 Armor this way but gain great support. Going with Force of Nature here goes without saying though. Best Magic Resistance piece in the game, gives you a nice health regeneration bonus, and gives you movement speed.
I put the Rabadon's Deathcap in there but really you can replace that with just about anything you may need at the time. A couple more support items like Randuin's Omen or Aegis of the Legion might be nice. But if you are going for the Omen, I'd suggest getting Heart of Gold as your first item, or right after you get your Sorcerer's boots, so you are raking in the money from an earlier stage of the game.