- Separate the numerals from the face cards and stack them face down in a pile accessible to all. Numerals count at face value from
Ace = 1 to Ten = 10. Face cards representing the 12 prime numbers from 23 to 79 inclusive can be left face up to
make them easily identifiable. Primes ending in 1 are spades, in 3 clubs, in 7 hearts, and in 9 diamonds, as shown below:
- To win the face cards by making equations equalling their values.
- There is no deal. One player - or each in turn; it makes no difference - turns the top three number cards and lays them face up in a row. If two of them are of the same suit everybody tries to make one of the target primes by multiplying together the two of the same suit and either adding or subtracting the third card. The first to call out a valid prime wins the face card representing it. If no one does so, turn the next numeral card and add it to the row. Keep going till someone makes a valid prime by multiplying together two numerals of the same suit and adding or subtracting any other numeral in the row.
- Winning face cards
- Whenever somebody wins a face card the row of numeral cards is gathered up and placed at the bottom of the numeral pack. Play then continues as before.
- Ending and Winning
- If four or more play the game ends when all 12 face cards have been won. For a quicker game two or three players may prefer to end when one player has captured primes totalling 100 or more.
- If two or more players call out different prime numbers the highest of them wins. If two or more claim the same prime number and the dispute cannot be resolved gather up the cards of the current row and return them to bottom of the numeral pile. (To prevent this, you may prefer to decree that it is not enough to call a prime card out: you must also be the first to clap your hand on it). If someone makes a false claim (in that the equation they make isn't valid) they are forbidden to make another call before the next numeral is added to the row.