A tackle is a fundamental part of football. A tackle is when a defensive player grabs onto or hits an offensive ball-carrier with their body with the intent of knocking the ball-carrier to the ground.
Tackling is essential to the sport as to prevent frequent scoring and the advancement of the football. If there was no tackling in football, the game would be a matter of which team can run down the field more times.
In football, a player is down when a specific part of their body touches the ground. When a player's knee, elbow, hip, head, or wrists touch the ground, they are called down. This primarily occurs when a player is tackled to the ground, in which it is called down by contact. A player is also called down in the case of certain penalties, such as an illegal forward pass. Out of bounds works the same as when a player is downed; the ball is placed at the yard line the player went out of bounds.
A player may also give themselves up or take a knee on purpose; these actions also count as being down. Occasionally, a player will appear to be down but keep running-as long as a whistle isn't blown by a referee, the ball is still live, although the play will likely be reviewed.
There are certain standards that a tackle must follow, mostly to prevent injuries of the players playing the game. Therefore, there are legal tackles and illegal tackles.
There are a few exceptions to where a tackle may occur. A defensive player can tackle an offensive ball-carrier almost anywhere to bring them to the ground, including grabbing their legs to trip them or using their body to push them into the ground. Grabbing a player from behind to pull them backward is also legal. Stopping forward progress, which is when a ball-carrier has stopped moving forward for a certain amount of time (usually a couple of seconds), results in a dead ball and stoppage of play. These tackles are all legal.
Illegal tackles are illegal because they often risk putting players in danger. Tackles to the head and shoulder areas are strictly forbidden and rules have been implemented to discourage this from occurring. Tackling a player by pulling on their facemask is also forbidden. Grabbing a player from behind around the neck and shoulder area is also illegal and is called an illegal horse-collar tackle. Offensive players cannot tackle defensive players unless the defensive player has gained possession of the football. A player cannot lead their tackle with their helmet, or a penalty will be called for a dangerous tackle.
The ball in football is called dead when one of these situations occurs:
There are some variations of these rules, depending on the league that play occurs.
The tackling rules for the NCAA are similar to that of the NFL besides a couple of differences. A player is down when a part of their body other than the hands or feet touches the ground, like the knee, elbow, hip, or head. In the NCAA, a player does not have to be tackled to be called down, unlike the NFL. There is also much more emphasis on leading with the helmet penalties. It is called much more often in the NCAA than in the NFL. The major difference for tackling penalties in the NCAA is that a player does not have to be tackled for the ball to be called dead. If a player possessing the ball falls to the ground, they are ruled down and the ball is called dead.
The NFL tackling rules are constantly changing. The most recent change to NFL tackling rules includes an emphasis on preventing head-to-head collisions by not allowing the kicking team to begin running on a kickoff until after the ball is kicked. Other than that change, NFL tackling rules have remained mostly the same. A player is ruled down when a certain part of the player's body hits the ground, like in the NCAA. However, a player in the NFL must be tackled to be ruled down by contact and can completely touch the ground while making a catch or running the ball. A player can also be called down by forward progress, in which they do not come in contact with the ground, but the defense has prevented them from gaining yards for a set amount of time.
The CFL has a similar rule to the NFL wherein a player must be tackled to the ground for the ball to be called dead, unlike the NCAA where a ball carrier falling to the ground results in a dead ball. The major difference between down rules in the CFL and NFL is that a kneel-down in the CFL does not result in a dead ball, but a 'rolling snap.' The downed player rules in the CFL are identical to the NFL rules on downed players.