O

Off (the Board): Said of those checkers already removed from the board during the bear off. To decide how many rolls it will take to complete a bear off you can look at the number of checkers you already have off.

On the bar: A checker awaiting re-entry after being hit as a blot. It takes an extremely unfortunate sequence of rolls to be stuck on the bar when your opponent has borne off their last checker.

One Point Game: See Ace Point Game.

On Roll: The player whose turn it is, is said to be 'On Roll'. The player ahead and on roll has an advantage in a race and should consider doubling.

Open Point: A point that is not owned by either player. The early game is a battle for possession of key open points.

Opening Roll: To start the game both players roll a single die and the player who rolls the higher number starts first using the numbers on both dice for the 'opening roll'. The most equitable opening roll moves have been calculated by the Bots but you are on your own after that.

Otter: The acceptance of a Raccoon and offering of another double at the same time while retaining possession of the cube. The otter is sometimes referred to as one of the 'furry rodents' involved in doubling.

Outer Board: The points numbered 7-18 and are not a part of either player's home board. When your opponent still has checkers to escape it is important to maintain control over your outer board.

Outfield: The outer boards.

Outside Prime: A prime consisting of points primarily in the outer board. An outside prime may consist of the 5 through 10 pts.

Own a Point: To have two or more checkers on a point. When you own a point, the opposing player may not land on it.

Own the Cube: To have the cube on your side of the board after your opponent has doubled you being the only one with the option to double. You gain a bit of equity simply by owning the cube.