The rules of Double Solitaire

The setup

Two 52-card decks, without jokers, are shuffled together: 104 cards, each one in two copies. 9 columns are dealt with 1, 2, 3, 4, 5, 6, 7, 8 and 9 cards, 45 cards in all: in each column, only the last card is face up, and the other 36 are hidden. The remaining 59 cards form the stock, face down. Beside it are the waste pile, empty, and 8 empty foundations.

Allowed moves

• On a column: a card goes on a face-up card of the opposite color (red on black, black on red) and one rank higher. A 7 of hearts goes on an 8 of spades or clubs.
• A sequence in one go: a face-up card in a column moves together with all the cards placed on it. Only the first card of the sequence has to fit the destination column.
• Duplicate cards: every card exists twice, so a black 6 has four possible places (the two 7s of hearts and the two 7s of diamonds).
• From the waste pile: only the top card can be played, onto a column or its foundation.
• A hidden card that is uncovered turns over by itself and becomes playable.

Rank runs from the ace (lowest) to the king: ace, 2 to 10, jack, queen, king.

The empty column

An empty column accepts only a king, alone or with the cards placed on it. No other card can go there, even to uncover a hidden card: the Examples page shows this refusal in a real game.

The foundations

There are 8 foundations, 2 per suit. Each one takes a single suit: the ace first, then the 2, the 3 and so on up to the king, one card at a time. In the app, each suit has its own row of two spots (spades, hearts, diamonds, clubs, from top to bottom): an ace goes on an empty spot in its own row, never on another suit's. A card dropped anywhere on the foundation area finds the foundation that accepts it by itself; if there are two, it goes on the first one in the row. The Examples page shows the second ace of spades taking the second spot.

The stock and the passes

You tap the stock to turn cards over onto the waste pile. The app offers two ways to draw, selectable in the New game window:

• Draw 1 ("Easy"): one card at a time; each card of the stock can be played in turn.
• Draw 3 ("Hard"): three cards at a time, fanned out on the waste pile; only the last one can be played, and the next one becomes available once you have played it.

When the stock is empty: in Normal scoring, a tap puts the whole waste pile back into the stock, face down, and you start again, with no limit on passes; each recycle costs 100 points. In Vegas scoring, the waste pile is not recycled: the stock can only be gone through once, in draw 1 as in draw 3.

The end of the game

The game is won when all 104 cards are on the foundations. The app does not declare a loss: when no useful move is left, you undo moves or start a new game.

What the app adds

These points are specific to the Double Solitaire app; other versions of the game do things differently.

• No auto-play: no card goes to the foundations by itself, and the game does not finish by itself. Tapping a top card sends it to a foundation that accepts it when possible; two quick taps (the "Double tap" setting, on by default) then look for a spot on the tableau (the longest column first, then an empty column for a king). You can also drag the cards.
• Taking back from a foundation: the top card of a foundation can be taken back by dragging and placed on the tableau, without gaining or losing points.
• Undo: the last 200 actions; undoing removes the points of the undone move, but the move counter does not go back down.
• Game code: each deal has a code (for example DS1-D1N-AAAAAAB) that gives you the same deal again, with its draw mode and scoring. See the FAQ.

Scoring in the app

Normal scoring

The score starts at 0 and never goes below 0: a recycle done early in the game therefore costs less than 100 points. A game won without taking back any card from a foundation always totals 1220 points for the 104 cards on the foundations and the 36 cards turned over, plus 5 for each card that came from the waste pile, minus the recycles.

Vegas scoring

There is no floor: the score stays negative as long as 20 cards or fewer are on the foundations, and turns positive at the 21^st. A game won without taking any card back from a foundation ends at +$416. The app writes the score in dollars: "$416", "$0" or "-$104".