A football team’s punter usually comes onto the field during fourth down. The punt is used when the offense decides it is unlikely to gain a first down and wants to move the opposing team farther from its own goal line.
American football gives an offense four downs to advance at least 10 yards. If a team has not reached that distance after three plays, it commonly punts on fourth down rather than risking a turnover on downs. The punter catches the snap and kicks the ball downfield, allowing the defense to begin its possession farther away.
Fourth down is not an automatic punting situation. Teams may instead attempt to convert, kick a field goal, or use a fake punt. A punt can also occur on an earlier down in unusual circumstances, but fourth down is the standard situation.
The punter is a specialist, separate from the placekicker in many teams. The kick’s purpose is field position, not scoring, and the receiving team may return it or let it roll dead.