Forty Thieves with one extra card dealt to every pile, five instead of four, turning a hard climb into a brutal one. Two decks, and just a 3% win rate.

Famous Fifty Solitaire takes Forty Thieves Solitaire and deals one extra card to every tableau pile, five instead of four. That single card buries just enough of the deck to turn a hard game into a brutal one, which is why Famous Fifty has a reputation as one of the toughest two-deck builds around. The game is difficult, with a 3% chance of winning, and it's played with two full decks.
Josephine Solitaire is a cousin from the same Forty Thieves family and a gentler one, since it lets you move whole sequences at once. Famous Fifty keeps the stricter single-card rule, so your odds of victory come down mostly to skill.
Every rule here traces back to classic Solitaire, the starting point before Forty Thieves piled on the difficulty.
If you run into anything odd or have an idea that would make the game better, please contact me.
Have a good time playing!
8 foundation piles: Build up from Ace to King in the same suit.
10 tableau piles: Build down in suit. At the start of the game, each pile is dealt five face-up cards.
Stock: Click to flip over cards one at a time to the waste. There are no redeals.
Waste: The top card is available to play to the foundations or tableau.
There are eight foundation piles.
Any ace may be moved to an empty foundation pile.
A card can be added to a foundation pile only if it's one rank higher and the same suit as the pile's current top card, so the only card that fits on a 5 of diamonds is a 6 of diamonds. There can be no more than 13 cards in a pile.
The top card of each foundation can be moved back into play if another pile will accept it.
Ten tableau piles of five cards each, all dealt face-up.
A card can be added to a tableau pile only if it's one rank lower and the same suit as the pile's current top card, so the only card that fits on a 10 of hearts is a 9 of hearts.
Cards on the tableau that are not covered by another card are free to be played onto the foundation or any other tableau pile.
Empty tableau spots may be filled with any card.
Only one card can be moved at a time, though turning on super-moves lets you shift several cards together whenever you have enough empty tableau columns to do the same thing one card at a time.
There is one waste pile, and the rest of the deck makes up the stock.
Clicking the stock deals one card face-up to the waste. There's only one pass through the stock, with no redeals.
The top card of the waste is playable to the tableau or foundation.