Activities Sports & Athletics False Start in Football - Definition and Explanation Share PINTEREST Email Print Quarterback Matt Barkley #7 of the USC Trojans is not happy after as an official calls a false start on the Trojans in the second quarter of a game against the Oregon Ducks. Steve Dykes/Getty Images Sport/Getty Images Sports & Athletics Football Basics Playing & Coaching Best of Football Plays & Formations College Football Baseball Basketball Bicycling Billiards Bodybuilding Bowling Boxing Car Racing Cheerleading Cricket Extreme Sports Golf Gymnastics Ice Hockey Martial Arts Professional Wrestling Skateboarding Skating Paintball Soccer Swimming & Diving Table Tennis Tennis Track & Field Volleyball Other Activities Learn More By James Alder James Alder is an expert on the game of American football, blogs for The New York Times, and appears on radio shows. our editorial process James Alder Updated March 17, 2017 A false start is an infraction in which an offensive player moves after he has taken a set position and before the ball is snapped. Once the offensive formation is set, the offensive linemen must wait for the ball to be snapped before making any moves. For players on the offensive line, a movement that triggers a false start call could be very minimal, such as shuffling of the feet just a couple of inches. False starts are one of the most commonly called penalties in football. The purpose of the rule is to try to prevent offensive linemen from unfairly drawing defensive linemen offside. If a false start is called, the offensive team receives a five-yard penalty and replays the down. When a false start is called the play immediately becomes dead. Offside Penalty In the same vain as the false start penalty is the offside penalty. An offside penalty occurs when a defensive player crosses the line of scrimmage prior to the snap of the football by the offense. For instance, if a player on the defensive line jumps and makes contact with a player on the offensive line before the quarterback receives the snap that results in an offside penalty. A defensive player is actually allowed to return to the proper side of the line of scrimmage after being offside if the ball has not yet been snapped, he does not make contact with any of the offensive players, and his being offside does not trigger a false start. An offside penalty can also be called during special teams play. It can be called on the kicking team during a kickoff if the players other than the kicker cross the line before kick contact is made. Like a false start penalty, an offside penalty is a five-yard penalty. Unlike a false start, however, when an offside is called the play does not immediately become dead. Instead, the play is run as usual, and the penalty is addressed after the play is completed. Then the offense has the option to choose the outcome of the play, or to simply accept the penalty. Thus, a play in which an offside penalty occurs is often called a ‘free play’ for the offense. Reasons for False Starts False starts often occur as a result of a miscommunication between the quarterback and members of the offensive line. The reason could be that linemen thought that the ball would be snapped before it was actually snapped, or that he misunderstood the signal called out by the quarterback. Extremely loud crowds can sometimes lead to false starts on the offense. Offensive linemen communicate with the quarterback through commands the quarterback calls out. When a stadium is especially loud, it can cause the defense to be unable to hear the quarterback’s calls, and potentially move before the ball is actually snapped. Crowd noise factors into the concept of “home field advantage.” Loud crowds are even sometimes referred to as the defense’s ‘twelfth man’, as they provide the defense with an additional advantage.