Kill

A kill, is the event of decreasing an enemy champion's health to zero while the enemy has no abilities or items to prevent death. Death may be prevented by certain effects, such as those granted by the item  and friendly abilities like, or delayed by passive abilities like  ,  and.

Rewards
The last player to strike the target champion is awarded with the kill, and all contributors within the last 10 seconds are awarded with an assist. If the champion killed has any transferable buffs  ( or  ), the killer champion gains all of these buffs and the duration of each buff is reset. When a champion is killed, the player who scored the final hit receives gold (50-500g) (on Howling Abyss maximum gold for a kill exceeds 500g) and experience. To reduce the effectiveness of feeders and snowballing lanes, less gold is awarded when a champion has a lower level than the killers. Additionally, a champion with many consecutive deaths will award a significantly reduced bounty, eventually reaching a bounty floor of 50 gold, nearly the gold value of a minion. The bounty will reset to 300 if said champion kills an enemy champion, or resets more gradually with assists or farming (refer to Bounty values Notes below for details). In gameplay, kills may be sacrificed in favor of securing a map objective, or due to other situational circumstances, such as the low health champion retreating into high risk enemy territory.

Execution
If a champion dies and hasn't been damaged or debuffed by another champion in the last 13 seconds, they are executed. Otherwise, the kill is awarded to the enemy champion who last dealt damage. Executions are caused by a turret, minion, or monster. An execution offers no gold but still grants experience to nearby champions on the opposite team when it is caused by a turret or minion.

In some cases it could be strategically advantageous for a player to purposefully be executed as an alternative to dying from an enemy champion; in doing so, the enemy receives no gold. Doing this on ARAM allows you to visit the shop without granting kills to the enemy team.

Note that executions do not end your killing spree.

Multi-kill
The act of killing several champions within 10 seconds of each other (30 seconds to Penta Kill after a Quadra Kill if no enemy respawns). The following comments are shown: "Summoner" has slain "(slain name) Summoner" for a [...]!'
 * Double Kill (2)
 * Triple Kill (3)
 * Quadra Kill (4)
 * Penta Kill (5)
 * Hexakill (6)
 * Legendary Kill (6+)

Ace
An ace is defined as killing the last living champion of the enemy team. Scoring an ace is far easier than scoring a pentakill, since the only requisite is for the entire allied team to kill the enemy team, rather than one person killing the entire enemy team. There is no gold bonus associated with aces.

Gold reward
The standard gain per kill is 300 gold. Every kill (in a row) by a champion increases their value (the reward gained for killing that champion) by 16.5%, up to a maximum of 500 gold. Each death (in a row) of a champion reduces its value, by 8.5% for the first death and 20% for every death afterwards, to a minimum of 50 gold. The bounty will reset to 300 if said champion kills an enemy champion, or resets more gradually with assists. Assists remove one stage of the death penalty each (if a champion was on his third death (220 gold), an assist would raise the value to that of two deaths (275 gold)). Every kill a champion achieves without dying (called a killing spree) increases that champion's bounty to a maximum of 500 gold as stated before. The gold bounty is not reset when the champion is executed without any enemy champion contributing to it. Being on a killing spree only affects the gold gained upon your death. First Blood (the first kill of the match) gives an additional 100 gold (400 total) beyond the basic amount for the kill.

Bounty values
Notes :
 * That gold values will continue to drop past the 9th death, eventually stopping at 50 gold. Also, with lower killing spree bounty cap and increased bounty gain, there is no additional gold for a shut down beyond the 4th kill.
 * Every 1000 gold earned from minions / monsters reduces the death spree by 1 death.
 * Kills are worth 75% of the base reward during the first 2 minutes of the game, scaling to 100% at 4 minutes. The bonus 100 gold gained from First Blood is not affected by this penalty

Items benefiting from kills

 * - Restores 15% of your max mana on kill or assist.
 * - +10% critical strike chance. Unique Passive - Avarice: Gain an additional +3 gold every 10 seconds. Unique Passive - Greed: Gain an additional 2 gold every enemy unit kill.
 * -  collects trophies when killing Champions and gains bonus effects based on how many trophies he has. Rengar gains one Trophy whenever he scores a kill or assist.
 * 3 Trophies: +25 movement speed while out of combat or while in brush.
 * 6 Trophies: Rengar's leap gains 125 bonus range.
 * 12 Trophies:  duration is increased by 5 seconds.
 * 20 Trophies: bonus movement speed is doubled.
 * - +15 ability power, +80 health, +3 mana regen per 5 seconds. Passive - Restores 4 mana when you kill an enemy unit.
 * - 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.
 * - Your champion gains +5 damage 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 +20% bonus attack speed.
 * and - Unique Passive – Rage: Basic attacks grant 20 movement speed for 2 seconds on hit. Minion, monster, and champion kills grant 60 movement speed for 2 seconds. The movement speed bonus is halved for ranged champions.
 * - Basic attacks deal 25 (+Devourer stacks) bonus magic damage. Scoring a champion kill or assist will grant 2 Devourer stacks and killing a large monster will grant 1 stack. 1500 Gold.

Skills benefiting from kills

 * (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.
 * (Active): Annie shoots a mana infused fireball, dealing magic damage to her target. The mana cost is refunded and cooldown halved if it kills the target.
 * (Passive): Ashe gains 3 bonus gold each time she kills a unit or destroys a structure.
 * (Passive): Whenever Cho'Gath kills a unit, he recovers health and mana. The values restored increase with Cho'Gath's level.
 * (Active): Target enemy takes true damage. If Feast kills the target, Cho'Gath grows larger and gains extra health and basic attack range, stacking up to six times. Cho'Gath loses half of these stacks, rounded up (Lost stacks being rounded up, thus, kept stacks rounded down), whenever he dies.
 * (Active): Darius leaps to target enemy champion and strikes a lethal blow, dealing true damage. For each stack of Hemorrhage on the target, Noxian Guillotine deals an additional 20% damage. Darius may recast Noxian Guillotine within 20 seconds if it kills the target.
 * (Innate passive): When Draven catches a Spinning Axe, or kills a minion or monster, he gains one stack of Adoration. When Draven kills an enemy champion, he consumes all of his Adoration stacks and gains 50 + (2 × per stack consumed) gold. Draven loses half of his Adoration stacks upon death.
 *  (Active): Evelynn removes all slows affecting her, gains bonus movement speed for 3 seconds and ignores unit collision. Champion kills and assists refresh Dark Frenzy's cooldown.
 * (Active): Fiora gains additional attack speed for 3 seconds. Each autoattack or Lunge she lands during this time increases her movement speed for 3 seconds, stacking up to 3 times. Killing a champion refreshes the cooldown on Burst of Speed. Assists reduce the cooldown by half of the base amount.
 * (Active): Gangplank shoots a target enemy with his pistol, dealing physical damage. If it is killed with this ability, he gains extra gold and refunds half the mana cost. This ability can critically strike and applies on-hit effects, including his passive.
 * (Active): Irelia dashes forward to strike her target, dealing physical damage. This applies on-hit effects. If it kills the target, Bladesurge's cooldown refreshes and refunds 35 mana.
 * (Innate passive): 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.
 * (Innate passive): After a kill or an assist, Katarina's cooldowns are reduced by 15 seconds.
 * (Toggle Off): When Karthus kills a unit, he restores mana.
 * (Active): Kha'Zix leaps to an area, dealing physical damage to enemies in the area. Kills and assists refreshes Leap's cooldown.
 * (Active): Malzahar infects his target's mind, dealing magic damage every half seconds for 4 seconds. If the target dies while afflicted by the visions, they pass the curse on to a nearby enemy unit, refreshing the duration and restoring mana to Malzahar.
 * (Active): For 10 seconds, Master Yi gains increased movement speed and attack speed, and becomes immune to slows. While active, champion kills and assists extend the duration of Highlander by 4 seconds.
 * (Active): Mordekaiser deals damage to the target and curses it for 10 seconds, stealing life. Damage is equal to a percentage of the target's maximum health. If the target dies while under the effect of the curse, their soul is enslaved and will follow Mordekaiser for 30 seconds. During this time, Mordekaiser gains 20% of their ability power and attack damage. The spirit gains 75% of Mordekaiser's adjusted damage, ability power, and health totals.
 * (Active): Nasus's next attack will deal additional damage. Siphoning Strike permanently gains 3 damage whenever it kills an enemy. The bonus is doubled to 6 stacked damage if the enemy killed by Siphoning Strike is a champion, large monster or large minion.
 * health bonus can be triggered by killing an enemy unit with any of Sion's damage sources, including autoattacks, champion abilities, summoner spells and item actives.
 * (Innate): Whenever Swain kills an enemy unit, he restores 9 (+1 per level) mana. On a champion kill or assist, he regains an additional 9% of his maximum mana pool.
 * (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.
 * (Innate passive): Whenever an enemy unit nearby to Trundle dies, he heals for 2/3/4/5/6% of its maximum health.
 * (Innate passive): Upon killing a unit, Twisted Fate rolls his dice, gaining from 1 to 6 bonus gold.
 * (Innate passive): On champion kill or assist, Varus gains 40% attack speed for 6 seconds. On minion kill, Varus gains 20% attack speed for 3 seconds
 * (Passive): Veigar gains bonus ability power for each champion kill from any damage source and 1 bonus ability power for each minion kill with Baleful Strike. The bonus is doubled to 2 AP if the enemy killed by Baleful Strike is a champion, large monster or large minion.

Masteries benefiting from kills

 * : Champion kills and assists restore 5% of your missing health and mana.
 * : Each time you kill a unit, you regain 3 health and 1 mana.