When
two players kill each other at the same
time. Most likely caused by the weapons being delayed instant-kills, such as
rocket launchers, but can more rarely happen with hitscan weapons (i.e. weapons with no projectile travel
time) should the players fire at the EXACT same
time. Environmental explosives (e.g. explosive barrels) or being in a heavily damaged vehicle (e.g. rocket launcher vs. car) can increase the likelihood.
In a duel or two-team match where the most kills wins, the trade kill results in no net gain of points since both teams earn a point. However, in the rare
case where one more kill will result in victory, even a trade will result in the leading team getting the victory. Some
game modes only provide score for kills on certain criteria (e.g. headshots), which will make a net zero-score trade kill harder, if not impossible, to get.
In Halo 3, I saw a dramatic trade kill. Two Choppers from
different teams
boosted into one another. Since Choppers can
even destroy other Choppers with their ram attack, both Choppers blew up and the drivers died.
