(Innate): When Rumble reaches 100 heat he overheats, silencing himself for 6 seconds to cooldown completely and causing his basic attacks to deal an additional 20 + (5 x level) + (0.3 per ability power) magic damage for the duration.
Tips :Rumble's passive is quite complicated to be honest. But once you have got your mind round the basic concept and understand how to use it and in what combos then everything will be fine!
You need to get it into your head already that the Electro Hrpoon will not let you charge the gauge well because of its big cooldown. Try to maintain your Heat with the shield or even the Firespitter, which would be easier.
Try to always keep your gauge at about 50% to profit from the passive even if it is not easy. Don't let it go down too quickly! Cast an eye over your gauge to make sure it isn't over charged either, unless you choose to do this. This would increase your damage in melee but you can forget about using your abilities in the time it will take for Rumble to de-charge (a bit like a silence).
In sum, it's all about the timing!
(Active): Rumble torches his opponents in front of him, dealing magic damage in a cone for 3 seconds. Does half damage to minions.
While in "Danger Zone", the damage is increased by 25%.
Tips :
Rumble's Flamespitter is an ecellent spell to harass in the lane and keep your heat gauge at 50%. Rumble's damage and gameplay depend on your passive do try to keep the famous gauge at 50% to play better.
Mainly to push and harass, don't hesitate to put pressure on your target to make him back the maximum number of times. This way he will miss the creeps and will also be behind in terms of levels.
This is a real massacre in teamfight, not with a chainsaw but a Flamespitter! You can also touch as many people as possible in your cone of action to do your maximum damage.
Magic Damage Per Second: 30 / 53.3 / 76.7 / 100 / 123.3 (+0.45 per ability power)
Total Magic Damage: 90 / 160 / 230 / 300 / 370 (+1.35 per ability power)
Enhanced Magic Damage Per Second: 37.5 / 66.7 / 95.8 / 125 / 154 (+0.56 per ability power)
Total Enhanced Magic Damage: 112.5 / 200 / 287.5 / 375 / 462.5 (+1.6875 per ability power)
(Active): Rumble pulls up a shield, protecting him from damage and granting him a quick burst of speed.
While in "Danger Zone", the shield strength and movement speed are increased by 25%.
Tips :
The shield has a very weak cooldown that lets you keep your heat gauge as high as possible without any problems.
It is not a very important shield but it is still good for controlling the damage for your opponent a bit or absorbing a DoT (ignite for example).
The movespeed bonus lets you chase an enemy more easily or escape faster.
Shield Strength: 50 / 80 / 110 / 140 / 170 (+0.4 per ability power)
Enhanced Shield Strength: 62.5 / 100 / 136.5 / 175 / 212.5 (+0.5 per ability power)
Movement Speed: 10 / 15 / 20 / 25 / 30 %
Enhanced Movement Speed: 12.5 / 18.75 / 25 / 31.25 / 37.5 %
(Active): Rumble shoots a taser that deals magic damage and applies a slow on the first enemy it hit for 3 seconds. A second shot can be fired for no additional cost within the next three seconds, even if Rumble overheats. If the second taser slows an enemy that has been slowed by the first, the slow is refreshed and its movement speed reduction is doubled.
While in the "Danger Zone", the damage and slow percentage are increased by 25%.
Tips :
Also a very good harass spell for the lane. The slow (as well as the speed bonus from your shield) will let you cling to your opponent and burst him with your Flamespitter. Since you have two harpoons, your target is basically going to suffer.
It's a good spell to last hit if you have an opponent who is putting too much pressure on you in the top lane or if you feel camped by the enemy jungler.
You should also note that your second harpoon has no Heat cost so you can use it as much as you want.
Magic Damage: 55 / 85 / 115 / 145 / 175 (+0.5 per ability power)
Enhanced Magic Damage: 68.75 / 106.25 / 143.75 / 181.25 / 218.75 (+0.625 per ability power)
Total Magic Damage: 110 / 170 / 230 / 290 / 350 (+1.0 per ability power)
Enhanced Total Magic Damage: 137.5 / 212.5 / 287.5 / 362.5 / 437.5 (+1.25 per ability power)
Slow: 15 / 20 / 25 / 30 / 35 %
Enhanced Slow: 18.75 / 25 / 31.5 / 37.5 / 43.75 %
(Active): Rumble calls down a line of rockets over the target linear location, using a click and drag targeting system. The rockets deal initial magic damage to all enemies hit on arrival, and also leave a trail of destruction for 5 seconds that slows by 35% and deals magic damage every second to all enemies standing on the area.
Tips :
An ultimate with a formidable ability to engage in a teamfight.
In the lane phase, use it if you think you can make a kill, on an opponent or in your jungler's gank. Otherwise it is not really necessary, keep it in case you get surprised on the top lane!
It is a straight AoE that slows everyone and deals a lot of magic damage in that line. It is up to you to try and place it well so that you hit the most opponents.
Cooldown: 105 / 90 / 75 seconds
Initial Magic Damage: 150 / 225 / 300 (+0.5 per ability power)
Area Magic Damage Per Second: 100 / 140 / 180 (+0.2 per ability power)
Total Magic Damage: 650 / 925 / 1200 (+1.5 per ability power)
Pros
Rumble has a pretty huge burst, make the most of it
You have good mobility thanks to the shield's movespeed
Your ability to chase is very good thanks to the slow + move speed
In teamfight you can do a lot of damage with your ultimate
Cons
You depend a lot on your early game, be careful not to mess it up or you will have difficulty making up for it
You don't have sustain in the lane phase, you should really take a Hextch revolver to remedy this