Note: The neutral zone is the space defined by lines drawn through the ends of the ball parallel to the yard lines when the ball is spotted and ready for play. No player may legally have any part of his body in the neutral zone when the ball is snapped, with the exception of the center.

Penalties against the offense
1.) False start (5 yards) - any player moving after they have gotten in their set position before the snap in a way that simulates the start of the play

2.) Delay of game (5 yards) - allowing the play clock to elapse before the snap

3.) Holding (10 yards) - illegal use of the hands or arms while blocking; an automatic safety is assessed instead if spot of infraction is within the offensive team's own end zone

4.) Offensive pass interference (10 yards) - interfering with a defender attempting to catch a pass

5.) Intentional grounding - throwing the ball into the ground to avoid being tackled
NFL penalty: 10 yards or spot of foul, whichever is farther from the original line of scrimmage, and loss of down
College penalty: Spot of foul and loss of down

In both NFL and college, intentional grounding from the offensive team's own end zone constitutes an automatic safety unless the defense chooses to decline the penalty, which might only ever happen if the infraction had occurred on a fourth-down play. If the quarterback has moved outside of the area between his offensive tackles (the "pocket"), there is no penalty for grounding the ball if the quarterback throws the ball past the line of scrimmage. There is also no penalty for "spiking" the ball to stop the game clock, by throwing it directly into the ground. However, such an action must be executed immediately after the snap of the ball, before the quarterback demonstrates intent to make a forward pass.

6.) Illegal blocks
· Illegal block in the back (10 yards) - an illegal block from behind and above the waist
· Clipping (15 yards) - an illegal block from behind and below the waist
· Illegal crackback block (15 yards) - an illegal block, from any direction, below the waist by any offensive player not on the offensive line (e.g. wide receivers, quarterbacks and running backs)

Penalties against the defense
1.) Offsides (5 yards) - Being across the line of scrimmage before the ball is snapped, or being in the neutral zone when the ball is snapped. When called, the official throws a flag, but the play continues.

2.) Encroachment (5 yards) - A "defensive false start," called when a defensive player contacts an offensive player or crosses the offensive line before the snap. When called, the official throws a flag and blows his whistle, stopping the play.

3.) Running into the kicker (5 yards) - during a kick from scrimmage

4.) Pass interference - interfering with a receiver's attempt to catch the ball.
NFL: this can be a devastating penalty because the ball is moved forward to the location of the interference, as if it had been caught.
College: An automatic first down. Penalty is 15 yards or the spot of the foul, whichever is closer to the previous line of scrimmage.
High school: 15 yards and an automatic first down

5.) Defensive holding or Illegal use of hands (5 yards and an automatic first down; in college, the chains are not moved if the previous play was 1st and 10, making the next play 1st and 5, as in "Offsides" or "Encroachment" above) - illegal use of the hands or arms either while attempting to ward off a block, or to cover a receiver

6.) Illegal contact (informally, illegal chuck, 5 yards and an automatic first down; in college, same exception noted in "Defensive holding" above applies) - any contact made between a defender and a receiver after the latter has traversed more than five yards beyond the line of scrimmage; this rule was adopted in 1978, and its enactment is regarded as contributing to the dramatic increase in both passing yardage and scoring the NFL has witnessed since that time.

7.) Piling on (15 yards and automatic first down) - unnecessarily falling on or jumping on any player who has already been downed

8.) Roughing the kicker (15 yards and automatic first down) - tackling the kicker after he has kicked the ball

9.) Roughing the passer (15 yards and automatic first down) - tackling the quarterback after he has thrown a forward pass. The defender is expected to make a reasonable effort to avoid the passer; if, once the ball is thrown, contact is imminent or inevitable, no penalty is called.

Penalties against either team
1.) Too many players on the field (5 yards)

2.) Grabbing the face mask (5 or 15 yards) - If there is pulling, twisting or turning, 15 yards; otherwise 5 yards. In college, any face mask penalty on the defense results in an automatic first down; in the NFL, only the 15-yard ("flagrant") face mask penalty results in an automatic first down, but in the case of a 5-yard penalty the down remains the same.

3.) Unsportsmanlike conduct (15 yards) - Any conduct by anyone involved in the game—usually a player, but occasionally a coach, and very rarely one or more spectators—deemed to be especially objectionable by the game officials, or by rule. The penalty is more strictly enforced in college football than in the NFL.