Suicide is the intentional act of bringing about one's own death. In a story-based game, this may be the result of horrible pain or fear, or simply preferring death to capture, as was the case with Call of Duty 4's Victor Zakhaev.
In a deathmatch environment, suicide is considered any action by which the player brings about his or her own death, either intentional or accidental. This may include blowing oneself with a rocket or similar explosive that causes splash damage or falling into a bottomless pit or other trap without being pushed by another player's weapon. In most deathmatch games, a suicide will result in a point deduction, usually one point for each suicide. For example, a player with 38 kills but 10 suicides will only have 28 points by match's end. In a team deathmatch environment, suicides may also be counted against the team's score in addition to that of the player. As such, it is obviously frowned upon to commit suicide often.