Rules of Ultimate

11. Out-of-bounds

11.1. The entire playing field is in-bounds. The perimeter lines are not part of the playing field and are out-of-bounds. All non-players are part of the out-of-bounds area.

Steinar's comment (unofficial!): Catching on the line

This means that if you are catching while one or both feet are touching the line, or are landing on the line after a catch, you are out-of-bounds.
11.2. The out-of-bounds area consists of the ground which is not in-bounds and everything in contact with it, except for defensive players, who are always considered “in-bounds”.
11.3. An offensive player who is not out-of-bounds is in-bounds.
1. 11.3.1. An airborne player retains their in-bounds/out-of-bounds status until that player contacts the playing field or the out-of-bounds area.
  
  Annotation: The “Greatest Play in the World”
  
  What: An offensive player realises that they cannot catch the disc in-bounds and jumps from an in-bounds position, catches the disc and throws it before they land out-of-bounds.
  
  Result: This is a valid pass.
  
  Why: Rule 11.3.1 states that an airborne player who jumped from in-bounds is still in- bounds. This lasts until the player lands out-of-bounds and by that time the player has already released the disc. Therefore, the disc is not out.
  
  Extra: A player is allowed to throw the disc while in the air, according to rule 18.2.1.1.
  
  A player may not catch their own “greatest” throw, unless it is touched by another player before the thrower catches it, as per rule 13.2.5.
  
  If there is a contested call regarding the catch after a “greatest”, the player who threw the “greatest” should be treated as the last thrower. They should establish a pivot at the point on the field closest to where they released the disc (or on the goal line if this would result in a pivot in their attacking end zone).
2. 11.3.2. A player who has caught the disc, who contacts the playing field and then contacts an out-of-bounds area, is still considered in-bounds, as long as they maintain the catch until they establish possession.
  1. 11.3.2.1. If they leave the playing field, they must establish a pivot point at the location on the playing field where they crossed the perimeter line (unless 14.3 is in effect).
    
    Steinar's comment (unofficial!): Pivot foot on the line
    
    Note that this rule talks about pivot point, not pivot foot. As long as your pivot point (the point you are rotating around) is in-bounds, your pivot foot can be on the line. See also annotation on 13.8.
3. 11.3.3. A thrower who contacts an out-of-bounds area is considered in-bounds until they make a pass.
  
  Steinar's comment (unofficial!): Pivoting out of bounds
  
  This means that after an in-bounds catch, you can set your non-pivot foot out of bounds; this is not a turnover.
4. 11.3.4. Contact between players does not confer the state of being in- or out-of-bounds from one to another.
11.4. The following are out-of-bounds turnovers, and no catch is deemed to have occurred:

Annotation: What to call when in or out

If an opponent believes an offensive player has caught the disc out-of-bounds they should make a call immediately by saying “Out-of-bounds” or “Out” for short. “Check feet” is a not a call and this call does not stop play.

The player making the “Out” call should be reasonably certain that the plyer was out otherwise they should not make the call.

If it is unclear if the player was out-of-bounds then play should stop as the players with best perspective discuss the call. Players may ask for perspective from people on the side-line, however it is still up to the players involved to make the final call. If the call is contested the disc shall be returned to the previous thrower.

Extra: For games played on unlined fields the receiver should be given the benefit of the doubt for close “Out-of-bounds” calls.

Annotation: Catch close to the sideline

What: A player catches a pass very close to the sideline and then goes out of bounds and establishes possession

Result: As long as the player catches the pass (by having a non-spinning disc trapped between at least two body parts) while also being in contact with the in-bounds area (and not being in contact with the out-of-bounds area) this is an in-bounds reception.

Why: Rules 11.3.2 means that once the player has caught the disc, they can go out of bounds, as long as they maintain the catch until they establish possession.

Extra: If the player who caught the disc in-bounds does contact out-of-bounds, and then fumbles the disc before they establish possession, that is an out-of-bounds turnover, regardless of whether or not they regain possession before the disc hits the ground.
1. 11.4.1. any part of an offensive receiver is out-of-bounds when they contact the disc; or
  
  Annotation: Receiving contacting out-of-bounds
  
  If the receiver’s feet are in-bounds, but their hair or clothing is touching the ground out-of-bounds, they are considered out-of-bounds.
2. 11.4.2. after catching the disc while airborne, an offensive receiver’s first contact is out-of-bounds while still in contact with the disc.
  
  Steinar's comment (unofficial!): First contact
  
  For the definition of “first contact”, see annotation on 14.1.1; if you catch the disc while in the air and land with both feet approximately at the same time, and one of them is out or touching the line, you are out.
11.5. A disc is in-bounds once play is live, or when play starts or restarts.
11.6. A disc becomes out-of-bounds when it first contacts the out-of-bounds area or contacts an out-of-bounds offensive player. A disc that has been caught by an offensive player has the same in/out-of-bounds status as that player. If the disc is simultaneously caught by more than one offensive player, one of them being out-of-bounds, the disc is out-of-bounds.
11.7. The disc may fly outside a perimeter line and return to the playing field, and players may go out-of-bounds to make a play on the disc.

Annotation: Leaving the playing field

Players are allowed to leave the playing field to make a play on the disc and may re-enter the field at any point. However it is a turnover if an offensive player jumps from out-of-bounds and contacts the disc before they contact the playing field (Rule 11.3.1/11.6/13.1.3).

Steinar's comment (unofficial!): Leaving the playing field

It is presumably also allowed to leave the playing field to avoid a dangerous situation, even if you are not making a play on the disc. E.g., if someone comes diving towards you, the safest option may very well be to make a jump out-of-bounds.
11.8. The place where a disc went out-of-bounds is the location where, prior to contacting an out-of-bounds area or player, the disc was most recently:

Annotation: Disc goes out of bounds

What: A long throw from the sideline doesn’t come back in field. Where do you set your pivot correctly and continue to play?

Result: A defender is always in bounds when making a play on the disc (11.2). This means that if a defender touches the disc whilst out of bounds – the disc is then played from nearest point on the central zone (11.8.2). Note: if a defender hits the disc but the wind takes the disc back in field - the play is still live.

Offensive players can become out of bounds (11.6). This means in the same situation if offence touches the disc first then it is a turnover and the disc goes back to where it crossed the perimeter line (i.e. was last in-bounds). (11.8.1).

If an offensive player jumps from in-bounds and touches the disc before landing, then that establishes a point where the disc was in-bounds. If this results in a turnover, without the receiver ever establishing possession, the disc will come into play at the point nearest to where the offensive player touched the disc. If the receiver catches the pass and throws it while in the air, and the disc lands in-bounds, then that establishes the disc as being back in-bounds.

Note: If players who had good perspective on the play cannot agree on where the disc went out-of-bounds, the midpoint between the two proposed locations should be used.

Extra: If a defender jumps, intercepts a pass, and then lands out-of-bounds, this is not a “double turnover” - the defender still retains possession.
1. 11.8.1. partly or wholly over the playing field; or
2. 11.8.2. contacted by an in-bounds player.
11.9. If the disc is out-of-bounds and more than three (3) metres from the pivot location, non-players may retrieve the disc. The thrower must carry the disc the last three (3) metres to the playing field.

Annotation: Non-player retrieving an out-of-bounds disc

What: A non-player retrieves an out-of-bounds disc and returns it to the thrower who is standing on the perimeter line.

Result: Rule 11.9 allows non-players to retrieve the disc, however the thrower must carry the disc the last 3 metres. Therefore the thrower should walk 3 metres away from the field and then return. They may then establish a pivot at the correct spot and continue play.

Extra: If the thrower commences play without going 3 metres away the opposition may call violation and play will restart with a check.

However if the opposition does not feel they have been disadvantaged by the disc being returned to the thrower, they can allow play to continue. Non-players may also stop an out-of-bounds rolling disc that is more than 3 metres from the pivot point.

The team in possession may choose to substitute a disc if the disc is out-of-bounds, and it will save time to substitute it. The thrower must still carry the disc the last 3 metres to the field. The thrower should notify the nearest defender if they are substituting the disc.

Note: Non-players should not intentionally touch a disc until it has become out-of-bounds.

Steinar's comment (unofficial!): Retrieving a disc for another player

You also are not allowed to retrieve a disc for a teammate. Once you pick up the disc, you have established possession (by the definition of possession); 8.3 says you cannot transfer possession during dead play, and 13.6 says you cannot transfer possession after a turnover.

You should not, in general, retrieve a disc for an opponent; even though it would be polite, you don't know who from the other team would want it (giving them the same problem as in the previous paragraph), and you may either be slowing their team down or giving them less time to prepare. If it's far out of bounds, though, it would probably be fine to take on the role of a non-player from the previous annotation and put it neatly on the ground three meters away from the field.