From the back of the box;
Prepare your fleet for the cosmic challenge of...
Four races of aliens have discovered Earth. All of them want to invade the planet, and they're not interested in sharing. The races agree to decide the matter in a space showdown. The winner takes all, with Earth as the prize.
But you don't have to be from another galaxy to enjoy this game. Space Checkers combines the luck of dice with the strategy of checkers. And you can even carry out a sneak attack by warping across the game board.
From the Rules sheet;
Object of the game:
To capture any 10 opponent pawns before any other player. A player captures an opponent's pawn by jumping over it.