Monte Carlo is one of the most popular forms of Solitaire with a deck of regular playing cards.
Components: one deck (52 cards)
Preparation: Deal 25 cards into five rows of 5 cards each.
Object: To discard all the cards in pairs of the same rank (eg pairs of "3"s).
How to play:
1. Select and discard pairs of cards of the same rank. Both cards of the pair should be adjacent in a row, a diagonal, or a column.
2. After discarding all possible pairs, move the remaining cards from right to left and from bottom to top to fill the empty spaces.
3. Deal additional cards from the stock pile to bring the number of cards back to 25.
4. Repeat until no possible pairs can be matched.
The amount of cards remaining counts as your minus score. The game is won if the entire deck is discarded by pairs.