Mexican Train is a popular domino variant that doesn't require lots of complicated twists and turns, unlike regular dominoes. One domino goes in the center, and everyone plays dominoes off the center in straight lines. Sound easy? It is! While Mexican Train may not have the strategy of more complex domino games, it is perfect for new players.
Shuffle your dominoes face-down and deal 15 to each player. Whoever has the double-12 tile (12 pips, or dots, on each side) places it in the center of the table, as the engine. (If no player has the double-12 tile, each player draws a tile. Repeat as necessary until someone has the tile, and plays it.) Whoever plays the double-12 tile as the engine will be the first player.
Take your first turn to start your train by playing a domino that touches the center engine. The side you touch to the engine must have the same number of pips as one side of the engine (for the first round, 12). If you are unable to start your train, you must draw one of the remaining face-down dominoes. If the new domino still does not match the engine, you will play no domino this turn. Once you have started a train, or drawn a domino and failed to, play proceeds clockwise and the next player starts a train.
Play a domino on your turn by matching the end of your train and extending it in a straight line with one additional domino. For example, if your first domino has 3 pips on the open end, you must extend it by playing a domino with 3 pips on one end next to it. (If you did not start a train on your first turn, you must start one now.) If you play a double domino (same on both sides), you must immediately play another domino. If you are unable to play a domino, you must draw one of the remaining face-down dominoes. If you are still unable to play a domino, your turn passes.
Optionally, if you have an additional domino that matches the engine, you may start the Mexican Train on your turn by placing an additional tile diagonally off of the center engine to start an extra train usable by all players. Once this "community" Mexican Train is started, nobody else may start another Mexican Train. However, any player may play on the Mexican Train as if it were her own train. (For example, if the Mexican Train ended with a 5-pip domino half, you could play a 5-pip domino half next to it.)
Continue play until one player plays his last domino. All other players score a point for each pip remaining on their unplayed dominoes. Begin a new round from Step 1, starting with the double-11 tile instead of the double-12. The round after that will use the double-10 tile, and so forth until the final round with the double-0 (blank) tile. After 13 rounds, the player with the lowest score wins.
Some variants require that you take your turn to play next to a double-domino (same on both sides), if any is available.