This is a strange game which is sketchily described on the Network Domino page of the Domino Plaza website. The scoring depends on the physical layout of the tiles in the tableau.
The game uses a double six domino set. The game is for two to five players.
Each player gets the same number of tiles. The left over tiles are put aside and are not used for the hand.
The player with the highest double leads. The following players take turns adding a tile to the network. A tile may be added to any open end of the network provided that:
- One end of the tile matches the suit on the open end of the network. That is, the usual connection rule applies.
- The tile being played does not match the sides of any other tiles while the numbers are different. [i.e. whenever a tile is played so that its side or end touches the side or end of another tile, the numbers on the tile halves that touch must be equal.]
- Corners with different numbers may touch.
- Doubles are played as spinners with four sides. [One tile can be played against each end of the double and one tile halfway along each side of the double.]
A player may play or pass. The game ends when all players pass in succession. [This may happen because the game is blocked, or because no one wishes to play, for fear of giving away a point to an opponent.]
Notes on what plays are legal
- Presumably, the player of a tile can choose the orientation in which it is played. Therefore a tile added to an open end of the network might be added in up to seven different positions (at the choice of the player), as in the following diagrams, where the red tile is the newly placed one:
- It's possible that both ends of the newly played tile other end will abut existing tiles in the network. One end of the new tile must abut an open end of the network. If the other end of the new tile also abuts an existing tile, rule 2 says that those adjacent numbers must also be equal. Such a play forms a ring and scores a point.
- Presumably, when a ring is formed, the end on which the tile completing the ring was played ceases to be open. Probably, if that tile connects two open ends, both cease to be open.
- Note that it can never be legal to play a new tile touching the previous tile all along one side, since it's impossible for both ends of the tiles to match.
A double can presumably be added to an open end in just four positions:
A new tile can presumably be added to the side of a double only in one way, but to an end of a double in three ways.
The last two are perhaps controversial, but if they are disallowed it becomes more difficult to complete loops.
A players earns 1 point for every ring he forms in the network.
Also, count how often each number appears at an open end of the network. The player contributing the last tile to the number appearing most often wins an extra 3 points.
The player with the highest score wins the game. The game can be played to some agreed upon total.
Notes on Rings
A "ring" is formed when a tile is placed to make a closed loop that completely encloses some space. The final tile will of course have to match at both ends, for example at A and B in this diagram:
The following play does not complete a ring, because the red tile only abuts the network at one end:
But the examples below are both valid rings, even though the one on the right is not a train in the usual sense: the tile marked 'X' has only one end involved in the ring.