An Assist is the action of helping an allied champion kill someone. You can either score an assist by hitting (without killing) the champion in the last 10 seconds before their death, or by contributing passively during this period of time.
When a champion is killed, the killer gets a certain amount of gold, while 50% of that amount is divided up among everyone who got an assist on it.
Secondary System
- Champions also gain assists on kills if they:
- Contributed to the battle via active abilities and basic attacks, for example stuns or knockups, whether or not they dealt damage to that enemy.
- Debuffed an enemy, even if that enemy was immune to the damage.
- Supporting a champion that contributed to the kill, e.g. healing or buffing an allied champion.
- Killing an enemy using
Trundle's 
Pillar of Ice or 
Veigar's 
Event Horizon (1 true damage each)
- Champions will not gain assists if they:
- ONLY use blind, reveal, or attack speed slow, without also contributing in any of the above ways.
Items Benefiting from Assists
- Mejai's Soulstealer - Your champion gains 8 ability power per stack, starting at 5 stacks and receiving 2 stacks for a champion kill or 1 stack for an assist. This effect can stack 20 times; you lose half of your stacks if you die. At 20 stacks, grants +15% bonus cooldown reduction. 1400 Gold.
Abilities Benefiting from Assists
- Akali's Shadow Dance (Active): Akali moves through the shadows to quickly strike her target and deal magic damage. Akali gains an Essence of Shadow once every few seconds up to a total of 3, affected by cooldown reduction. The time to gain a charge doesn't count when at maximum charges. Additionally, Akali gains an Essence of Shadow for a kill or an assist.
- Evelynn's Dark Frenzy (Active): Evelynn removes all slows affecting her, gains increased movement speed for 3 seconds and ignores unit collision. Champion kills and assists refresh Dark Frenzy's cooldown.
- Jinx's Get Excited! (Innate): Whenever a champion or tower that Jinx has dealt damage to within the last 3 seconds is killed or destroyed, she gains 175% movement speed that decays over 4 seconds.
- Katarina's Voracity (Innate): Katarina reduces the cooldown on all of her abilities by 15 seconds whenever she scores a kill or assist on a champion she damaged within the last 3 seconds.
- Kha'Zix's Evolved Wings (Active): Kha'Zix leaps to an area, dealing physical damage to enemies in the area. Kills and assists refreshes Leap's cooldown.
- Master Yi's Highlander (Active): For 10 seconds, Master Yi gains increased movement speed and attack speed, and becomes immune to movement speed slows. While active, champion kills and assists extend the duration of Highlander by 4 seconds. Champion kills and assists reduce the remaining cooldown of Master Yi's other abilities by 70%.
- Swain's Carrion Renewal (Innate): Whenever Swain kills an enemy unit, he regains 9 + (1 × level) mana. On a champion kill or assist, he regains an additional 9% of his maximum mana pool.
- Tristana's Rocket Jump (Active): Tristana fires at the ground to propel herself to a target location, dealing magic damage and slowing surrounding units by 60% for 2.5 seconds when she lands. On kills or assists, Rocket Jump's cooldown resets.
- Twitch's Ambush (Passive): When an enemy champion with Deadly Venom dies, Ambush's cooldown is reset.
- Varus' Living Vengeance (Innate): On champion kill or assist, Varus gains 40% attack speed for 6 seconds. On minion kill, Varus gains 20% attack speed for 3 seconds.
Masteries Benefiting from Assists
- Dangerous Game: Champion kills and assists restore 5% of missing health and 5% of missing mana.
