In poker, a PKO (Progressive Knockout) tournament is a type of tournament where a portion of the buy-in goes toward a bounty on each player's head. In PKO tournaments, when a player eliminates another player, they typically receive a cash prize for half of the eliminated player's bounty.

In a Progressive Knockout Tournament, each player has a bounty on their head which increases with each elimination. As a result, as the tournament progresses, the bounty on your head increases, making it more and more lucrative for other players to try to knock you out.