Dont have much of a intro sense this is my first build and just want to explain on how to use Rumble... (also this is incomplete, i will finish it later when i have more understanding with Rumble and not too lazy to update)

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 prot©g©s, 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.

''Ugh, it's gonna take forever to scrape your face off my suit!'' - Rumble

about the runes, just get either defense or magic runes, the ones i have provided on top are just the runes i have... its really up to you on what you want xD

First i would get a dorans shield cuz its awesome, but if u have armor runes or health runes and you think your tanky enough get a boot with 3 hp pots, after get blasting wand, giant belt,then after this decide on either sunfire cape or rylais... after getting both finish your boots with either sorcerer's boots or mercury treads depends on if they have alot of cc or not...then just get abyssal sceptor, rabadons deathcap, and a guardians angel... :)

usually i would either take flash or ghost and teleport... you can take either exhaust or ignite if you want but thats up to you... i dont use them so i dont know if their good or not...

Pros-

Good harrasser
Pretty good early/mid game
dont really need any cooldown items because skills are spammable
danger zone gives extra dmg, movement spd, etc...
Pretty good in a team fight
overheat gives alot of melee magic dmg
you do alot of aoe dmg

Cons-

sometimes spam too much and go to overheat which throws you off if your new to him
not really that great late game
hes melee, :/
do alot of dmg but cannot carry if goes late game...
timing and aim takes a while to get used to...

when laning, you should harrass alot with flamethrower because you can just spam it, dont go to oveer heat unless their close to you and should build up to danger zone... when ulting make sure u use it during the teamfight because you want to hit alot of people with it so be wise on where you put it...also use it for the kill cuz ur ult has super range xD

In Summary, i can only say that im still testing stuff on Rumble and wont be completeing my build anytime soon, but this is usually my build for now, so far its been pretty good...Anyways try it out for yourself and see wut its like...O.O