Seven. You have your five linemen (two tackles, two guards, and a center), and there also has to be two skill position players on the line of scrimage. It's usually a tight end and a wide receiver, but it can be different depending on the formation.
The offense must have 7 players on the line of scrimmage.
The offense is allowed up to ten players on the line of scrimmage, need one to receive the ball from the center. But the offensive is required to have a minimum of seven players on the line of scrimmage. Defensively all eleven can play on the line of scrimmage.
On the offensive side, nobody has to be in a down position on the line of scrimmage, but there must be six men on the line. The defense does not have any regulations as to where they must line up on the line of scrimmage.
Rules require at minimum 7 players to be on the line for any play. If a goal line offense has a RB and FB then the line might have 8 on the line.
Seven, of which two are eligible receivers. All other offensive players must be at least one yard behind the line of scrimmage (the exception being the quarterback) for one second before the ball is snapped.
On the offense, at least seven, though technically you can have more if you wish. On defense there are no requirements.
15 players total is the answer. Here is the breakdown. 7 players from each side must be in position on the line of scrimmage plus the quarterback for a total of 15 players on the field during a play.
There has to be 11 players on offense and Defence for every play. There has to be at least 7 players on the line of scrimmage prior to the snap of the ball. This applies to both offense and defence
Seven on offense. No requirements for the defense
10-12
When the ball carrier is tackled and does not pass ball to teammate or the ball is out of bounds, the play is called a scrum, and the yard line where the last play was downed is called the line of scrimmage. -----In American football, draw a line from sideline to sideline where the ball is put into play on each down and that is the line of scrimmage.
The offense has to have at least seven men on the line of scrimmage. There are no such requirements for the defense. So although you'd never see it happen, there could theoretically be as few as seven people on the field.