In gridiron football, the long snapper (or deep snapper) is a center on special teams whose duty is to snap the football over a longer distance, typically around 15 yards during punts, and 7–8 yards during field goals and extra point attempts.
During field goal and point after touchdown attempts, the snap is received by the holder, typically 7–8 yards away. During punts, the snap is delivered to the punter from 13–15 yards away. Following a punt snap, the snapper often executes a blocking assignment and then must cover the kick by running downfield and attempting to stop the opposing team's punt returner from advancing the ball in the opposite direction. If the punt goes uncaught, it is the snapper's responsibility to make sure the ball does not enter the end zone or bounce backward resulting in loss of yards. The majority of snappers at the highest levels of competition are specialized, meaning that they uniquely play the position of snapper, or have limited responsibilities elsewhere.
A good punt snap should hit the target—the punter's hands at the abdomen or waistline—between .65 and .75 seconds and with a tight spiral for easy handling. A "bad snap" is an off-target snap which causes the delay or failure of a kick or forces the punter into some other potentially compromising situation.
Long snapper was not always a dedicated position. Until about 20 years ago, the position of long snapper would be filled by a random player or lineman who was not getting playing time. The thought to have a roster spot reserved for just a snapper was ridiculous. Over time, people started to realize how important the role was, as one bad snap could lose any game. In the past 20 years, teams have not only trained and recruited true long snappers, but they even offer scholarships because of the importance of the position.
College rules are such that any of the 11 players on the punting team are allowed to proceed downfield at any time once the play has begun (unlike the NFL where only 2 players, the left and right gunners, are allowed to pass the line of scrimmage before the ball has been kicked). This results in many teams employing a "spread punt" or "rugby-style" scheme designed to maximize downfield coverage and limit returners from making larger gains the other way after receiving the ball.
In the NCAA, Defensive players are not able to line up within the shoulder length frame of the long snapper. Defensive players who play opposite of the long snapper are also not allowed to initiate contact with the long snapper until 1 second after the ball has been snapped. These rules were created to protect the long snapper, as they are in a compromised position with their head usually down and unprotected.
Unlike college, NFL rules do not provide for a set period of time after the snap before the long snapper can be engaged by the defense. However, no defensive player can line up directly in front of the long snapper when the offense is in a kick formation. Officials generally enforce this rule through verbal admonishment to an offending player prior to the snap. If the defensive lineman moves into a legal position before the snap, no penalty flag is thrown.
Before specialization, the long snapper often was a player who primarily played another position, mostly assumed to be backup centers because they perform regular snap duties to quarterbacks, and also to quarterbacks positioned further out in a shotgun formation. However, a recent example would be Allen Aldridge, who started at linebacker for the Detroit Lions and also served as the team's long snapper. This allowed the team to dress another non-specialist player. Now, every team in the NFL has a specialized long snapper, a trend born on the Washington Redskins in 1971, where head coach and general manager George Allen made George Burman the first modern long snapper — someone whose roster spot was based on the long snap, and not other positions. 
Long snappers are usually amongst the least-known players in the NFL, because of their highly specialized and relatively invisible role on the field. They are also generally not drafted, rarely appear on trading cards, and normally are acquired as undrafted free agents, with a few exceptions:
Despite their anonymity, a team lacking a skilled long snapper can be seriously undermined. A famous example of this was on January 5, 2003 during the 2002 wild card playoff game between the San Francisco 49ers and New York Giants. During the regular season, the Giants suffered missed field goals due to the lack of an experienced long snapper, and signed Trey Junkin out of retirement to be the snapper for the playoff game. Junkin botched a snap on a field goal attempt that could have won the game for the Giants, who had led 38–14 at one point in the game. Brad St. Louis of the Cincinnati Bengals was another long snapper who, besides having already botched two snaps in clutch situations in 2005 (wild card play-off game against the eventual champions Pittsburgh Steelers) and 2006, gained even bigger notoriety in 2009, when he delivered five bad snaps on either field goal or extra point attempts (leading to missed, aborted or blocked kicks) in the first five games of the season, which led to the then ten-year veteran being released from the team.
In 2008, it was the Pittsburgh Steelers that had long snapper problems. During an October 26, 2008 game against the New York Giants, the team's regular long snapper, Greg Warren, was injured with what was eventually revealed to be a season-ending torn ACL. Linebacker James Harrison, who had served in 2003 as the long snapper for the Rhein Fire of NFL Europe, volunteered to replace Warren. In the fourth quarter, Harrison's first and only snap sailed over punter Mitch Berger's head and through the end zone for a safety. This tied the score and gave the Giants good field position on the ensuing kick, resulting in the go-ahead touchdown late in the game. Warren sustained a second ACL tear in December 2009, though this occurred on the last play of a December 20 game against the Green Bay Packers, giving the Steelers adequate time to sign replacement Jared Retkofsky, who had also been signed to replace Warren after his injury in 2008.
In 2012, Raiders' long snapper Jon Condo was injured and was backed up by Travis Goethel, a linebacker for a game against the San Diego Chargers. On two occasions during the game, punter Shane Lechler was unable to handle snaps that had bounced prior to reaching him. On another attempt, Lechler took his position much closer to the line of scrimmage than is normal for a punter, so as to decrease the distance Goethel needed to accurately snap the ball. Though the snap was adequate, the decreased distance resulted in a blocked punt.