Number of players: 1
Type of Dominoes Used: Double 12
Type of Game: One player game

Object of the game. To arrange the 12 double tiles from the set into a circular formation, each double being positioned in the same place as it would appear on a clock face. For example, the 1-1 tile would be placed in the formation in the same location the 1 would appear on a clock face; the 2-2 would be placed where the 2 would appear; and so on.

Remove the double-blank tile from the deck. Shuffle the remaining tiles, facedown. Draw 12 tiles, and then place them, faceup, in a circular shape, placing the first tile at the point that will be considered "12:00" (where 12 would appear on a clock face), and continue by placing the second tile at '1:00' and so on, proceeding clockwise. Finally, place the double-blank tile inside your circle, at the very top, so as to "point to 12:00."

After the initial layout is finished, draw tiles one at a time from the deck, seeking to place each tile face up on top of another tile in your clock formation. When placing one tile on top of another, at least one end of the tile you are playing should match at least one end of the tile you are covering.

If you drew the 6-10, you could play it on the 3-10, 6-1, or 4-6. The best play, however, is likely to be on the 4-6 at the "10:00" time slot, in case you soon draw the 10-10.
By the way, never place a tile on top of a double, whether the double is in its correct time slot or not.
Except when it's a double tile, if you are unable to play the tile drawn from the deck because there is no match, place that tile aside, never to be drawn during the remainder of the game.

When you draw a double that has no match on the clock at all or when you have a double on the clock but in the wrong place, this is called a "double in trouble." The 7-7 at "4:00' in the drawing is a "double in trouble."

When you have a "double in trouble," you may move the top domino of any pile to the top of another pile, as long as at least one end of the tile being moved has the same number of pips as at least one end of the tile it is being placed on top of. Continue making as many such moves as necessary in order to bring any "double in trouble" to its correct time slot. You may even empty an entire time slot in this way, creating a blank space.

If you cannot fill a blank time slot with its correct double, fill it immediately with a new tile.

As soon as you place a double in its correct time slot, turn that tile, along with all the tiles underneath it, so it radiates out.
If you draw a double that cannot be played anywhere, the game is lost.
      

      Variations: This game may be played,with a double-9 set, in which case your clock face will not be a complete circle, starting with "1:00" and going to "9:00."
      You may also play this game with a set of double-6 dominoes, using a half-circle for your clock face or dealing the 6 tiles in a straight row, if you prefer.