Kill assist

A Kill Assist

“

Click to listen

— The Medic on his kill assist

”

A kill assist is awarded to a player when an enemy that they have wounded is killed by another teammate.

Participating in a kill assist may sometimes produce a special audio response from your class. Using the "Thanks!" command moments after the assist will also make your class use these responses.

Example

Killer + Assister

Target

Consider the example demonstrated in the image

A BLU Pyro called Assister is using a Flamethrower on a RED Scout called Target.
Assister stops attacking. Target has suffered direct damage from the Flamethrower and is now on fire.
A BLU Demoman called Killer places Stickybombs beneath Target and then detonates them.
The Stickybombs kill Target. They also happen to kill Killer because he's too close when they detonate.

Result

Killer is awarded a kill because the Stickybombs dealt the last damage to Target.
Assister is awarded a kill assist for damaging Target prior to Killer.
Assister is not awarded a kill because his attack was not the one that killed Target.
The killfeed notification for a kill with a kill assist: Killer + Assister (Killer's Weapon) Target. A zoomed-in view of the notification is featured at the bottom of the image.
Killer's death from the Stickybomb splash damage does not affect either his kill award or Assister's kill assist award.

Gaining kill assists

Priority

If several people help in getting a kill, then the one who is highest in the list below will get the assist.

Soaking the victim in Jarate.
Healing the killer at the time of the kill (this includes healing disguised enemy Spies, even if the healing beam breaks upon kill).
Engineers healing the player with a Dispenser will also receive the Kill Assist bonus.
Lighting the victim on fire, provided they are still on fire at the time of the kill. (The last player to light them on fire gets priority.)
Wounding the victim. (The player who dealt the most damage gets priority.)
Boosting the killer with the Buff Banner, Battalion's Backup or Concheror.

General

Other ways that you can gain kill assists include:

Upgrading or restocking a fellow Engineer's Sentry Gun with your Wrench.
Stunning the victim with any stun capable weapon, such as the Sandman.
Airblasting the victim shortly before the kill.
Marking the enemy for death with the Fan O'War.

Additional notes

They are worth half a point and will be counted as a full point every two assist kills.
If multiple players wounded the victim, priority goes to the player who dealt the most damage. Some methods of gaining kill assists will have greater priority than others. Unlike captures which award points to multiple players, only one assist is possible for every kill.
If the person who receives a kill assist is being dominated by the victim, they will get a revenge kill. It is possible for both the killer and the assister to get a revenge kill if the victim was dominating both. Similarly, it is possible to dominate a player by getting four kill assists on them.
Unlike Pyros receiving assists when someone who was lit by them is killed, a Medic will not receive an assist if a player he has healed or overhealed recently scores a kill and he isn't healing him at that moment. A Medic will only receive an assist kill if his patient kills someone while he's being healed.
It is actually possible to assist yourself by throwing Jarate and then killing your target or by hitting them with the Sandman's baseball and killing them. If the enemy kills himself (fall damage, the Demoman's explosives, the Soldier's rockets or his Kamikaze taunt) you'll still receive credit for the kill.
Even though no damage is done, if a Pyro compression blasts an enemy who is killed shortly afterward, the Pyro receives a kill assist.
While Jarate grants a kill assist, Mad Milk has no assist score given to the Scout.