Capture the flag, commonly abbreviated as CTF, is a traditional outdoor game where two teams each have a flag (or other marker) and the object is to capture the other team's flag, located at the team's "base," and bring it safely back to their own base. Enemy players can be "tagged" by players in their home territory; these players are then, depending on the agreed rules, out of the game, members of the opposite team, sent back to their own territory, frozen in place until freed by a member of their own team, or "in jail."