O

On Roll - The player whose turn it is to move.

On the Bar - Where a stone is placed after it is hit.

Open Division - The main division of a tournament where any player may enter.

Opening Game - The first stage of a backgammon game where the players have yet to fix on their initial game plans.

Opening Roll - The first roll of the game in which both players simultaneously roll one die.

Open Point - A position on the board which is not occupied by two or more of the opponent's stones.

Open Tournament - A tournament open to any player regardless of strength or experience.

Otter - An immediate redouble by a player who has just accepted a raccoon.

Outer Board - The side of the board away from where the players bear off their stones.

Outer Table - Outer board.

Outfield - The outer board, particularly points nine, ten, and eleven.

Overplay - Make an unnecessarily big play.

Own a Point - To have two or more stones on a point so that the opponent is blocked from landing or touching down there. To have an anchor on that point.

Owner of the Cube - The player who was last doubled.

Owns the Cube - The player who last accepted a double is said to own the doubling cube or to have possession of the cube.