Abilities
Rumble's spells generate Heat; at 50% Heat, abilities gain bonus effects; at 100%, he Overheats, gaining attack speed and empowered attacks but cannot cast spells.
Rumble torches a cone in front of him for 3 seconds, dealing increased damage in the Danger Zone.
Rumble gains a shield and burst of speed, enhanced in the Danger Zone.
Fires a harpoon that slows and reduces Magic Resist; Danger Zone boosts effects. Holds 2 charges.
Rumble fires rockets that create a burning wall, damaging and slowing enemies who touch it.
Guide
Rumble excels at area denial and sustained damage in ARAM; manage your heat to overheat at key moments for bonus auto-attack damage, and use your ultimate to control the narrow lane.
Tips
Use your Flamespitter (Q) to zone enemies in the narrow ARAM lane.
Activate Scrap Shield (W) before engaging to absorb poke damage.
Overheat before teamfights to maximize auto-attack damage with The Equalizer (R).
Build Liandry's Torment for sustained burn damage against grouped enemies.
Use The Equalizer (R) to cut off escape routes or force enemies off the health relic.
Combos
Electro-Harpoon (E) slow into Flamespitter (Q) for guaranteed damage.
Scrap Shield (W) dash forward, then Flamespitter (Q) while overheating.
The Equalizer (R) to zone, then Electro-Harpoon (E) to catch fleeing targets.