The object is to be the first to cap off your 5x5 grid.
On your turn, you roll the five dice (each of which is 0-0-0-0-1-1). Each die that comes up 1 earns you a cap and the opportunity to roll again. If you choose to do so, you roll the 0 dice in the hope of getting more 1s...But if you roll no 1s, you lose your turn and any 1s rolled previously. Hence the Temptation. If you manage to get five 1s, you place five caps (see below) and take another turn.
The caps won must be placed in a straight orthogonal line, adjacent to at least one previously placed cap. You lose the caps won if you can't place them. You may even cap off part of another player's grid --this helps him somewhat, but may make the rest of his grid harder to cap off, by breaking up the pattern.
When playing multiple rounds, the winner of a round scores the other players' remaining cap spaces.