Passball is similar to touch football, except:
You can only advance the ball by passing, not running.
Everyone gets to do everything: passing, catching, punting and kicking. There are no specialized positions.
As in touch football, two teams take turns trying to advance the ball into the opponent's end zone, or to kick a field goal.
The team on offense has three downs to advance the ball to the next zone on the field. A zone is the area between two 5-yard markers on a standard football field. When a pass is caught in a zone, the line of scrimmage is then the border of that zone closest to the opponent's end zone.
For example, if a pass is thrown from the offense's 25-30 yard zone and caught at the 37 yard line, the new line of scrimmage is the 40 yard line, and the offense has a first down.
As long as the offense advances to further zones within 3 downs, they retain possession of the ball. If they fail to advance (and do not punt or attempt a field goal), possession goes to the other team in the current zone.
The passer is the player currently in possession of the ball. A player is designated the passer the instant they catch a pass, kickoff, punt or interception. All other players are eligible receivers.
When there is no stoppage of play (for a turnover, penalty, timeout, etc.), passing plays can be continuous - as soon as a pass is completed, the receiver becomes the passer. No lineup or snap is required before the next pass.
After receiving a pass, the player is free to move about the zone in which they caught the ball, but they must remain behind the new line of scrimmage. It is not permissible to advance the ball to a further zone by running.
A pass can be overhand, underhand, or anything other than a direct handoff. Receivers must be at least three yards away from the passer in all directions to discourage bucket-line types of plays and give the defender a reasonable opportunity to cover them.
An onside pass is one that is completed within the current active zone. It does not result in a first down, nor does it cost a down - play continues as normal after any other completed pass.
If the ball is intercepted, the other team gains possession and the interceptor is now the passer. There is no stoppage in play, and they can immediately attempt to pass to teammates from the zone where the ball was intercepted.
Play is stopped in the following cases:
After an incomplete pass
When a timeout is called
When the ball is turned over on downs
Prior to a declared field goal attempt
When a penalty is called
After a scoring play
There is no stoppage of play on completed passes unless a penalty has been called.
There are two ways of restarting play after a stoppage:
An onside start occurs after a timeout, turnover on downs, or missed kick. All receivers start behind the line of scrimmage, and all defensive players are on the opposite side.
An offside start occurs after an incompletion or penalty. Receivers are not required to line up onside, they can be anywhere on the field and in motion at any time.
To start play in either case, the passer simply stands still, holds the ball and calls "Go", loud enough for most players on the field to hear it. The Go call can be preceded by other signals or audibles, but there is no silent snap count and the ball does not need to be snapped off the ground.
The passer may elect to punt the ball to the other team on any down (usually, but not necessarily, the third down). There is no need to declare the intention to punt. A recipient of an onside pass may not punt the ball, it must be the original passer on that play.
The punting team’s players do not need to be onside during the punt, but they cannot in any way interfere with anyone receiving the punt.
The offensive team can attempt a field goal at any time during their possession. This must be declared to the official, play is stopped and they are allowed 20 seconds to set up and attempt the kick. If the kick is successful, 3 points are awarded and the team on offense kicks off. If it misses, the defensive team is awarded the ball at the line of scrimmage for an onside start.
After scoring a touchdown, the team on offense can attempt to convert the touchdown by kicking an uncontested field goal off a tee, from a distance of their choice. Points awarded for converts are based on the distance from which the kick is attempted: 1 point from the 15 yard line, 2 from the 25, 3 from the 35, and so on.
All place kicks (kickoffs, field goals and converts) must be performed by the next player in the kicking rotation, to ensure that everyone gets a chance to kick. This does not apply to punts.
For more details about all aspects of the game, see the Complete Rules.