Rumble is an AGRESSIVE SUPPORT who is an Ability Power based champion.

***Tools you will need to succeed***
EXPOSE WEAKNESS
E Ability Electro-Harpoon
W Ability Scrap Shield
OPRESSION
Fleet of foot
Summoner spell EXHAUST
WARDS and red potions are a must Especially the Health potions Early on.

WARNING: If you do NOT ward you wont be able to see this Guide or any guide for that matter's potential.


***What YOU MUST KNOW about Rumble Support***
Rumble support is based around Poke/slow/buff.

Disclaimer: DO NOT PLAY RUMBLE PASSIVELY, You must get in the fray. You must have your ADC follow up on all Harpoons hits to play him properly as a support as seen in this guide.

Your Job:Buff your ADC's target damage, while trying to Tank enough incoming damage for your ADC to secure the kill.
This is why you need 5 points into offense to get EXPOSE WEAKNESS.
EXPOSE WEAKNESS coupled with your E Ability (Electro-Harpoon) significantly Boots your Lane's trade potential for around 6 seconds.
Expose Weakness gives your ADC 1% increase damage for 3 seconds after you have already hit them with some pretty decent AP poke damage, Not to mention the target that is slowed for 3 seconds in addition you can Cast another E Harpoon for free with no CD extending the damage buff duration to a maximum of 6 seconds.

*****6 SECONDS OF TRADE POTENTIAL SO WHAT?????***
Taking 12 points in Defense is crucial. mainly for the health, armor, and Magic Resist. However, Why you're really in the Defensive Tree is for OPRESSION This Nerfs your target Opponents damage by 3% essentially negating the 1 point they've put into Havoc at the very bottom of the Offensive Masteries tree.

***Utility***
Finally you will need 13 points into Utility
You'll need Greed & Scavenger to keep up on gold since you wont be getting last hits on minions.
You need Fleet of Foot coupled with your movement speed burst from Scrap Shield to Get IN and OUT of Position Quickly to land your E ability Electro Harpoon, and avoid getting hit by CC and skill shots.

Disclaimer: DO NOT PLAY RUMBLE PASSIVELY, You must get in the fray. You must have your ADC follow up on all Harpoons hits to play him properly as a support as seen in this guide.
Now we can move on.

Q: Why play Rumble Support?

A:
1.) IT'S FUN as hell.
2.) FREE ABILITIES! Rumble's abilities have no cost related to them, and the use of his abilities is only limited by cooldowns.
3.) SCRAP SHIELD! Ever 6 seconds (before CDR) Rumble can pull up a shield, protecting him from damage & giving him a burst of movement speed.
4.) POKE! Your E (Electro-Harpoon) has long range, its free, its slows, and you can cast it a 2nd time for free again and it will double the slowing effect.
5.) Game changer Ultimate! It's estimated at around 1000 yards lenth, pretty good range and The rockets leave a trail of destruction for 5 seconds, dealing magic damage every second and slowing all enemies standing on the area by 35%.
6.) Great AOE damage with his Q.
7.) you can manipulate your passive to increase your melee damage (by overheating).
8.) Highly Mobile due to Scrap shield's speed burst. Helps with Warding/chasing/escaping/getting back to lane and also positioning.

Q: Where Should I be in Team Fights?

A: With this build rumble Can be a very effective OFF Tank. you generally want to hang out between your real tanks and your Squishy team-mates. Somewhere you can Peel enemies off your squishy AP/AD carry's with your E ability Slows.

Q:Who should I play Rumble against?

A: Anyone. Rumble's popular Counter-picks tend to Focus on Rumble as Top-lane bruiser expecting Rumble to Maxing out his Q ability, Which You wont be doing till very last. Making Rumble a good support pick because not many people know how to counter him.

Q: How to I use his ultimate?!?!?!?!

A: It's Tricky at first. but once you get the hang of it, It's a real punishing Game changer.
Just like any other skill shots it helps to send it straight down the lane. especially to clear a minion wave if you're solo defending a turret.
mainly you want to drop it right on top of whoever is attacking your AP carry & AD Carry to help peel enemies off because of its slow ad damage over time. Also You can use it to Break up the enemy Team in Team fights to separate anyone out of position but it only lasts 5 seconds so its up to your team to take advantage and get somone killed before the wall goes away.

Q: How do I play Rumble?

A: Read the Into to this guide. Its very easy to Play him once you learn manage Heat/overheating.

Pros:
Having a Shield at the click of a button with extremely low CD
great peeling and slows
Movement speed bursts for chasing and running away
Game changer ultimate.
Managing your heat properly gets you 25% increased damage/slow/shield.

Cons:
Rumble has a small learning curve due to the potenial gains from managing your Heat.
Unique game mechanics take a small amount of time to get use to, and if you overheat you can not use any ability.
Does not have a bubble or stun or heal the way some other supports do.

Masteries: 5/12/13

5 in Offense
4 CDR
1 EXPOSE WEAKNESS

12 in Defense
2 block
2 enchanted armor
1 unyielding
3 veteran's scars
1 in OPRESSION
1 juggernaut
2 in hardiness

13 in Utility
3 fleet of foot
1 scout
3 summoners insight
1 alchemist
3 greed
1 scavanger
1runic affinity

Runes:
9 Magic pen reds
9 Armor yellows
2 CDR blues, and 7 Scaling AP blues
3 AP Quints.

Starting Items:
Start with Ancient coin, a red pot, and a ward.
Buy Doran's shield on your 1st back along with boots if you have the extra gold.

core Items, Sorcerer's Boots, Rylai's crystal scepter, Locket of the Iron Solari.
After building these core items its okay to sell your Ancient coin. Don't sell the Doran's shield until You can afford some more Defensive items or AP defenive items.
SightStone is optional, though I think you should skip it.

For defense: Zhonyas hourglass, Rylai's Crystal scepter, Abyssal scepter. or Randuin's Omen

For Offense: Rylai's Crystal scepter, Rabbadon's Death cap, Liandry's tormnet, zhonya's hourlgass.

I will be Updating this Guide in the upcoming weeks with pictures, Videos, and Links please take the time to learn Rumble as a support it is highly rewarding.