For 2 - 4 players, 7 years or older (best with 2 or 4).
Players attempt to collect as many cards as possible, by turning cards over so that the sum of the numbers on them is as close to 13 as possible.
The cards are well shuffled and dealt out onto the table face down so as to form a 6 x 10 rectangle. Each player takes all the marker pieces in one colour.
First choose a player to start. Play proceeds in a clockwise direction. The player whose turn it is turns over cards, making sure that all players can see which cards they have turned over. As they turn over the cards, they must add the numbers on the cards together. They are trying to get as close to a sum of 13 as possible.
As soon as the sum of the cards turned over exceeds 13 then the player's turn is over. They must turn all the cards back as they were. Their turn also ends in the same way if they turn over 2 "0" cards.
If a player manages to turn over cards so that their sum is exactly 13, then they must pick up all the cards that they have turned over. They then return one of them, face down, onto any free space on the table, the rest are placed in a pile face down in front of them. The next player then takes their turn.
A player who has not yet reached 13 may decide to stop. In this case they mark every card that they have turned over with a wooden marker in their colour. Play then passes to the next player. The marked cards remain face-up.
Once there are marked, face-up, cards on the board, then the next player must attempt to better the sum of the face-up cards. They may not use the marked cards to do this. If they fail to reach the sum of the marked cards, or they exceed a sum of 13, then their turn is over, they turn all the cards that they have played back face-down, and the next player takes their turn.
If however they manage to turn over cards with a higher sum than the marked cards, without reaching or exceeding 13, then the marked cards are turned back over, and the markers returned to their owner, while the newly turned cards are marked. These now make up the new target.
If the newly turned cards total exactly 13, then the player takes the cards, returns one to the table, face down, and piles the rest up in front of them as above.
If a player reaches the same sum as the already marked cards, but uses more cards to get there, then this counts as an improvement, the new cards are marked and the previously marked cards are turned back over.
If a player's turn comes round again, and his markers from the previous round are still on the table, they pick up all those cards and place them face down in a pile in front of them, except for one, which they return face-down, to the table as above. This completes their turn for this round, they do not turn over any cards. The next player then takes their turn.
If a player only turns over one card, and this remains face-up with a marker for a full turn, then the player picks up that card, and adds it to their pile of scoring cards. The game is then over and the player with the most cards in their pile in front of them has won the game.
In the last round it might happen that players can not turn over cards, since all cards on the table are marked.