21 THE GAME. The new card game specially for 21st birthdays. The new card game especially for 21st Birthdays. "21 The Game" is full of all kinds of appropriate 21st Birthday facts, quotes, trivia and more. The aim of the game is to be first person to "HIT 21" (of course! What else could it be ?) "21 The Game" is new and different. Ideal as a small 21st gift. A little extra entertainment for any 21st !