Kills are most often used in community card poker variants like Texas hold 'em, which normally use blinds as the primary forced bet, and this article assumes such a game is being played, but the concept can be made to work with almost any poker variant with only minor changes to suit the betting protocol of the game.
Kill games serve to mitigate wins by "dumb luck" or "flukes".
They also serve to mitigate "bad beats", which are wins by a player who made questionable choices from an odds standpoint.
Thus, kill hands encourage a more disciplined, "tighter" betting style (less likely to call/raise and more likely to fold).
Kill games among a table of more experienced players also create a heightened thrill of risk; a player is on a winning streak, or a big pot has just been won, and the next pot is likely to be bigger.
One common value is ten times the value of the large bet (in a $20/$40 game, the kill would be active if the previous pot won was greater than $400).
Another common way a kill is activated is when a single player wins two pots in a row.
In high-low games, typically the kill is activated when one person takes the whole pot (known as "scooping"), either by having both the winning high and low hands, or by having the winning high hand when no low qualifies, though in some games the pot must exceed a specified amount for the kill to be triggered.
The amount posted is most often twice the normal big blind or small bet for that game, known as a "full kill".
Another variant concept, related to the use of the half and full kill in the same game, is the "double-kill".