When your opponent doubles and you think you are the favorite, you may "Beaver" - turn the cube an additional level, keeping control of the cube. You can only do this after you have been doubled. A "Raccoon" means that if you Beaver, the opponent who doubled can have the cube turned yet again and take control of it.
redouble. In backgammon, to beaver is to redouble and maintain control of the cube, an optional rule.
an immediate re-double by a player who has just accepted a doubling of the stakes from his opponent
When one player doubles and the second player immediately redoubles.
This is a rule agreed by both players prior to the game commencing, whereby upon doubling, your opponent may re-double straight away and retain ownership of the cube.
An optional rule whereby a doubled player may demand that the stakes be quadrupled instead of doubled, while retaining possession of the cube. This demand must be made before the doubler has thrown. When your opponent offers you a cube where you are actually the favorite to win it is often proper to offer a beaver if they are allowed.
When using the doubling cube, to instantly redouble the number on the cube after accepting a double. The player then retains possession of the doubling cube.
A beaver is a common rule meaning that a player is able to immediately redouble when offered the doubling cube, whilst still retaining the cube and not giving it back to the opponent.
When one player doubles, and his opponent immediately redoubles.
Re-double. See backgammon doubling rules