FreeCell

1. All 52 cards start face up in 8 columns: 7 cards in each of the first 4 columns, and 6 in each of the others.
2. Build the columns down in alternating colors. A red 9 goes on a black 10.
3. Each of the 4 free cells at the top left holds one card. Park a card there to reach the cards under it.
4. Any card, or a run of cards, can go into an empty column.
5. Move all the cards to the 4 foundations at the top right, by suit from the ace to the king, to win.

The rules move one card at a time. When a run has room to move card by card through the free cells and the empty columns, the game moves the whole run in one go, and counts it as one move.

The most cards you can move at once is the number of empty free cells plus 1, times 2 for each empty column. With 2 empty free cells and 1 empty column, that is (2 + 1) × 2 = 6 cards. A run that goes into an empty column cannot use that column, so the same table moves 3 cards there.

Each game has a number from 1 to 1,000,000, and the same number always deals the same cards. Send a friend the number, or the link after a win, and you play the same game. Games 1 to 32,000 are the same deals as in the FreeCell that came with Windows, so game 617 here is game 617 there. All of them can be won except game 11982.

• Phone and tablet: drag a card or a run, or tap it to send it to its best place: a foundation, a column, then a free cell.
• Mouse: drag, or click a card. A double click moves it once.
• Keyboard: the arrow keys move the blue ring. Enter sends the cards to their best place, and Space picks them up and puts them down. U undoes a move, and H shows a hint.

• Every card is face up, so plan before you move. Find the aces and the 2s, and free them first.
• Keep the free cells empty when you can. Each full cell makes the runs that you can move shorter.
• An empty column is worth more than a free cell: it doubles the run that you can move.
• Undo has no limit. If a plan fails, go back and try another one.