OFL football looks amazingly like what you already know. Instead of tackling, or using flags, we "tag" ball-carriers with two hands. We otherwise block, throw, catch like any other form of the game.
The offense has four downs to reach the next 'Line to Gain', otherwise the ball is turned over.
The field is 75 yards long (plus two end zones) and is broken into quarters—each 15 yards long, and marked by a cones. These cones mark the 'Line to Gain'.
The Lines to Gain do not move or change. It is typical that offenses may encounter both first-and-short situations or first-and-long situations.
A offensive player is considered "down" when a defensive player tags with ball-carrier with two hands fully contacting the body (one hand if the player is on the ground). Touching the arms only or only clothing (i.e. a small bit of T-shirt or the scrimmage vest), or tagging with fingertips, does not constitute a successful tag. Additionally, the ball does not count as part of the body.
For safety's sake, if a ball-carrier is on the ground, any touch is considered down-by-contact. Two hands are not neccesary.
Grabbing a ball carrier's clothes to stop him/her is a penalty. Tackling is not allowed.
Note: THE PLAY IS DEAD WHEN A DEFENSIVE PLAYER SAYS "GOTCHA". The offensive player is down when and where the defensive team claims the tag occurred. Period.
Note: a QB is down the moment he/she is tagged, regardless if the arm is in motion.
As such, defensive players should be very sure they have applied a legal tag before yelling "Gotcha". A false tag is a penalty - it stops play dead, and everyone gets mad and the whole thing generally sucks.
Probably the most consistently argued-about event at an OFL game is the tag. This is why a legal tag is important.
Again: Tags must be two hands to the body. Not arms. Not fingertips; not to a piece of shirt or the ball. Two hands to the body.
The defender -- once he's made the tag -- should then loudly say "I Got Ya!" or "Down!" or something. Yelling "I Got Ya!" before actually tagging a ball-carrier is not cool (yes, it happens a lot..) The play stops when you announce "Got Ya!" or "Down!" Therefore if you say it before you actually get the ball-carrier, you're cheating.
Teams have ONE time-out per half to plan a complicated play, manage the clock etc. Injury stoppages or field goal attempts (clock stops) don't count as a time-out.
While OFL play is very similar to other styles of the game we do have slightly different rules.
Each team has a team captain. The two captains will confer with each other and the Commissioner on controversial situations. If the two captains cannot agree on a course of action, the Commissioner will rule on the play.
In the event that teams have unequal numbers the following rules apply:
At the end of the game if one team is losing by more than 8 points, that team is allowed a single "X-point play", either a final "Hail Mary" pass after their final fourth down (i.e. a "fifth down") or, assuming they have scored a touchdown on the final possession, an "X-point conversion" attempt. In either case, the "X-point play" is worth however many points it takes to tie the game.
Teams that are down by 8 points or less must try to win or tie the game the old fashioned way.
The Line of Scrimmage can be set by players from either team. A standard yellow penalty flag is used to mark the current spot of the ball and the subsequent line of scrimmage.
Technically the defense is responsible for spotting the ball - this becomes important in two-minute drills or other 'hurry up' play. Not moving the flag to the new spot in a timely manner is a Delay of Game penalty.