Step 1 : Introduction to the question "1. Every backgammon set contains two dice. What is the name of the "extra" cube in each backgammon set?"
...1. the blitz 2. the doubler 3. the slot 4. the diamond The "third die" in backgammon is called the doubler. It is used during a money game when a player thinks he/she has an advantage over the opponent. The player places the doubler cube on "2" and offers the opponent a choice, to continue the game at double the original stakes, or concede now. If the opponent declines the offer, the game is terminated at single stakes; if the opponent accepts, the game continues at double the stakes. The player who accepts is then in control of the doubler; if he/she wishes to double again at a later point in the match, the doubler will then move up to "4" if the offer is accepted.