Fives and Threes is a networked dominoes game for up to four players, although it works just as well when played against the computer. The object being to score points by playing your dominoes so that the open ends of the line add up to multiples of five and/or three.

There are many variations on the basic game, but these are the rules used by this Fives and Threes. Configurable variations are shown in brackets.
1.There are four players. The computer will create dummy players if necessary.
2.Each player draws six dominoes. (Variation: start with any number up to seven.)
3.In the first round the player with double-six starts. If no one has double-six, then the player with double-five starts, or double-four etc. In subsequent rounds, the first double is one lower then the previous rounds, with double-six following on from double-blank. (Variation: the first player may start with any double, or with any domino at all.)
4.Each player now takes it in turn to add a domino to either end of the line of dominoes, so that the numbers on the adjacent ends are the same. If a player cannot play a domino, then he "knocks", i.e. presses the Knock button, so the other players know, and then misses his turn. (Variation: the next player who can play a domino, scores an additional point for each preceding knock.)
5.If the sum of the exposed ends of the line of dominoes adds up to a multiple of five and/or three then the player scores a number of points based on that multiple. For example, if the exposed ends on the line of dominoes added up to 6, then the player scores 2 points since 6 = 2 x 3. If the exposed ends add up to 12 then the player scores 4 points, since 12 = 4 x 3. If the exposed ends add up to 15 then the player scores 8 points, since 15 = 5 x 3 and 15 = 3 x 5. A table of possible scores is given below.
6.Play continues until a player has used all his dominoes, or no player can lay any more dominoes. (Variation: the player who finishes ("chips-out") scores one additional point.
7.The dominoes are then shuffled and each player draws again for the next round.
8.The game continues until a player reaches 61 exactly. If a player is on 60 points and scores two points, then those points don't count. He has to gain one point to finish on exactly 61. (Variation: play continues until 121, or any number, and the target score need not be reached exactly.)
9.Variation: Players are partnered with the player opposite. Another variation is that one or both partners must chip-out before the round ends.

The license of this software is Free Trial Software, the price is $15, you can free download and get a free trial.