A Kill Game is a variation of any fixed-limit betting structure game, generally a poker game. When the game is “killed” the stakes of the game, are doubled. If when playing $2-$4 Omaha 8/b with kill and the game is killed, the next hand will be played at $4-$8 stakes. The doubling is not cumulative if consecutive winning hands qualify as a kill and are always double the original stakes of the table. There are also half kill games where the kill (the amount put into the pot instead of calling the blinds by the winning player) is 150% larger than the big blind.
A hand can qualify as being killed in different ways for different games. In high-low split games if a player scoops a pot (wins both the high and the low hands, or wins the high with no low possible) and the pot is larger than a set monetary value, that player receives a Kill Button and is required to kill the next hand by posting an amount double that of the big blind prior to the cards being dealt. In some other games, such as stud or lowball, a kill is achieved when any player wins consecutive hands. After the second hand is won they receive and keep the kill button for the duration of the next hand which they are required to kill by posting an amount double the big blind in value. As long as that same player keeps winning, they keep the kill button, and continue killing the next pot.
The kill button has no influence on action at a poker table, the player with the kill button still acts in proper turn after the player to their right. The kill button is considered inactive if the player to whom the button would belong quits the game before the next hand. A player new to a game may not play in a killed hand unless they agree to kill the next un-killed hand. If a player is unaware of the kill and have attempted to limp in for the regular stakes they must post the full amount of the kill in a required kill game, and have the option to withdraw their bet and reconsider if it is not.
There are many rumors as to the exact origin of the phrase "kill game." On its basic level, it represents the excitement of a hunt, as games with kill such as Omaha are already rather wild with larger average hands winning (hence the common practice of "drawing to the nuts in Omaha) and the kill makes huge hands even bigger. On another level the players who qualify to post the kill blind have probably been making a "killing" financially in recent hands, and that too may contribute to the phrase's creation. A player new to a kill game are dead money, as the more agressive nature of the game will at first force them away from some of their good hands, while later encouraging them to play worse starting hands.
Sources
Poker terms
www.pokertips.org
www.cardplayer.com
countless 12-hour sessions in card rooms