In American football, a trap run or trap play is a run consisting of a defender on the line of scrimmage getting trap blocked by an offensive lineman or back from the opposite side of the ball. The play is known as a "trap" because the strong side offensive lineman will "block down" on a linebacker, seemingly leaving a defensive lineman unblocked. As the defensive lineman comes through the seemingly open gap/hole, he is "trapped" by the weak side guard who blocks the defensive lineman's blindside. Occasionally, a trap block will come from a tight end. Trap blocks by tight ends are known as "wham" blocks.