Two-deck variant
A challenging two-deck patience game. Two central reserve columns form the “Backbone” flanked by eight Rib tableau piles. A single “Coccyx” card sits at the base of the Backbone and must be played first before the Backbone cards become available. Build all 104 cards onto eight foundations in suit from Ace to King to win.
Play the Coccyx card first, then use Backbone and Rib cards to build the foundations.
SolitareGames includes classic builders, pairing games, and larger two-deck patience variants, so you can jump between quick rounds and longer strategic layouts.
Backbone is a structural puzzle as much as a card game because the Coccyx gate determines when the central reserve truly opens.
After freeing the Coccyx, you manage Backbone cards, Rib tableau piles, and a limited stock while building eight suit foundations from Ace to King.
Need more detail? Read the Backbone strategy guide.