FreeCell is a solitaire card game played using the standard 52-card deck. It is fundamentally different from most solitaire games in that very few deals are unsolvable, and all cards are dealt face-up from the very beginning of the game. Although software implementations vary, most versions label the hands with a number (derived from the seed value used by the random number generator to shuffle the cards).
Microsoft has included a FreeCell computer game with every release of the Windows operating system since 1995, greatly contributing to the game's popularity. It is so definitive for many FreeCell players that many other software implementations strive for compatibility with its random number generator in order to replicate its numbered hands.
One standard 52-card deck is used.
There are four open cells and four open foundations. Some alternate rules use between one and ten cells.
Cards are dealt face-up into eight cascades, four of which comprise seven cards each and four of which comprise six cards each. Some alternate rules will use between four and ten cascades.
The top card of each cascade begins a tableau.
Tableaux must be built down by alternating colors.
Foundations are built up by suit.
Any cell card or top card of any cascade may be moved to build on a tableau, or moved to an empty cell, an empty cascade, or its foundation.
Complete or partial tableaus may be moved to build on existing tableaus, or moved to empty cascades, by recursively placing and removing cards through intermediate locations. Computer implementations often show this motion, but players using physical decks typically move the tableau at once.
The game is won after all cards are moved to their foundation piles.