When you think of solitaire, you might picture a relaxing, winnable game. The forty thieves card game, however, is a different beast entirely. It’s a classic for a reason: it’s one of the most challenging and strategic single-player card games you can find, and it’s notorious for its low success rate.
https://play-solitaire.io/forty-thieves
So, what sets it apart from its more common cousins like Klondike?

First, the forty thieves card game uses two full decks. At the start of the game, 40 cards are dealt face-up into ten “tableau” piles (the “forty thieves” you have to outwit), and the rest are left in a stock pile. Your goal is to build eight foundation piles, starting from Ace and going all the way to King, one for each suit.