Players lay bets against the bank.  Players then pick a number between 14 and 18.  They then roll the die and total the values thrown until they reach a total over twelve. 

If the total is 13 they lose and the operator takes the wager (after all 13 is unlucky).  If the total is the number they chose they win and receive back their wager plus an equal amount from the banker.  If any other total is thrown, no one wins or loses. 

The banker knows that it has been mathematically proven that 13 is more likely to be the total than any other number.