Forty Thieves Solitaire

Forty Thieves is a two-deck solitaire with ten columns that start fully face up. Nothing is hidden on the table, yet the game is famously stubborn: you move one card at a time, you may go through the stock only once, and most random shuffles cannot be won at all. It rewards players who look several moves ahead and punishes careless draws.

Rules step by step

1. The deal. Two full decks, 104 cards, are shuffled together. Ten columns of four cards each are dealt face up. The other 64 cards form the stock.
2. The foundations. Eight foundation slots sit along the top, two for each suit. Each one is built up from the ace to the king in a single suit, so you will finish with two complete piles of every suit.
3. Build down in one suit. A card can go on a card of the same suit that is one rank higher. A 6 of hearts goes on a 7 of hearts and nowhere else.
4. One card at a time. Only the exposed card at the bottom of a column can move. There are no runs to carry, even when several cards are in perfect order.
5. Empty columns take anything. When a column runs out of cards, any card may be placed there, not just a king.
6. Draw from the stock. Click the stock to turn one card onto the waste pile. Only the top waste card can be played. When the stock is empty it stays empty: there is no second pass.
7. Win when all 104 cards sit on the foundations.

The page shows time and moves, plus how many cards have reached the foundations.

Why most deals cannot be won

Published estimates put the share of winnable random deals at about one in ten. A shuffle is usually lost before you touch it: a low card lies under a stack of cards that can only go back on a column if exactly the right partners show up. Because you build only in one suit, the number of legal moves is small, and a single misstep can cut off a whole suit.

Strategy

• Look at the whole table before every draw. The stock cannot be replayed, so a draw you did not need is a card lost for good. Make every useful move first.
• Free a column early. An empty column is your only parking space. Pick the column with the fewest cards or the shallowest low card and work it out first.
• Use the twin copies. Every card exists twice. When both copies are available, play the one that unblocks more, and keep the other as a landing spot.
• Count before you send a card up. If the second copy of the next lower rank is still in play, a card that goes to the foundation may have been the only place it could land. Aces and twos are safe to send up at once.
• Do not bury a card you need soon. Placing a card on a column makes everything under it harder to reach. Prefer moves that expose a card over moves that only tidy up.
• Test a plan with undo. Undo is free and unlimited here. Try a line, see where it leads, and step back.

Frequently asked questions

Is every deal winnable?

The default deals come from a pool that an offline solver has checked. The solver sees every card, including the order of the stock, and found at least one winning line for each pool deal. Our solver, given a short time limit, found a winning line for about one random deal in seven, and the rest were left out. A win is still hard to find, since you cannot see the stock the way the solver did. Pool deals also lean toward easier wins than a random shuffle, because only deals the solver could finish are kept. A deal that does not come from the pool is labelled as not checked.

Why does the game feel so hard?

Moving a single card at a time and building in one suit leaves little room to repair mistakes. Even with a known solution, you have to find a very particular order of play.

Can I go through the stock again?

No. Forty Thieves allows one pass. After the last card is drawn, only the tableau and the waste top can still move.

Why are there two foundations for each suit?

Two decks mean two aces of each suit, so two piles per suit are built at once. A card goes on whichever pile is ready for it.

Can I undo a move?

Yes, as often as you like, and redo too. Using the hint marks the game as played with help in your own stats. The hint shows a legal move, not a good one.

Related games

If you like the slow planning of Forty Thieves, try FreeCell, where all cards are face up and most deals can be won. Spider uses the same two decks with a different goal, and Klondike is the classic seven-column game. Today’s shared deal for each game is on the daily page, and all the rules are on the how to play page.

Last updated 2026-10-30