Under the gun

Under the gun is a position in a poker game.

A player is considered to be "under the gun" if they are the first to act in the preflop betting round. The term is most commonly used in describing the player to the left of the big blind in a game of Hold 'em or Omaha.

Being "under the gun" is one of the worst possible positions a player can have in a poker game; since they have to act first, they must act before knowing anything about how other players will play their hands. They have the least information available to them in making their decision about which action to take.