Heat:Rumble gains 20 / 10 Heat every time he uses a basic ability, and loses 10 Heat per second after 4 seconds of not using his abilities, increased to 20 Heat per second 2.5 seconds after.
Danger Zone:Rumble's basic abilities are enhanced at 50 Heat or above.
Overheating: At 100 Heat, Rumblesilences himself for 6 seconds, which he cannot mitigate or cancel by any means, but his basic attacks each deal 25 - 110 (based on level)(+ 30% AP)bonusmagic damage for the duration, during which his Heat also decays to 0.
Although it visually appears as and is termed a silence, overheating does not prevent Rumble from using summoner spells or item actives, only his own spells. The exception is the second cast of Electro-Harpoon, assuming the first cast overheats him.
Passive:Rumble stores a charge of Electro-Harpoon periodically, up to a maximum of 2 stored at once.
Active:Rumble shoots a harpoon that deals magic damage to the first enemy it hits and slows them for 2 seconds. Charges of Electro-Harpoon stored prior to overheating can be used even while overheated. The slow is enhanced if used on the same target.
Unlike all other forms of slow stacking, two harpoons on the same target will have their slows calculated additively.
Movement speed cannot be reduced below 110, and that slows that would reduce below 220 are modified. To put it another way: a reduction of 105% will not reduce you to 0 movement speed, but rather it will reduce you closer to 110 than a weaker slow would.
Each cast counts as a separate spellcast for the purposes of abilities such as Force Pulse and Sheen.
Active:Rumble calls down a line of rockets down the target path which remains for 5 seconds, dealing magic damage every second to all enemies within and slowing them by 35%. The Equalizer can be fired in any direction from any point within range.