Mexican Train is a dominoes game for 2 to 8 players. While you could play it with nothing more than a large pack of dominoes, it's more fun if you include pieces that simulate a train yard: a miniature train turntable and miniature colored trains for each player to mark their track and to represent the Mexican Train.
To win a game of Mexican Train, a player must be the first to place all his box cars (dominoes) on his train (line of dominoes), the other players' trains or the Mexican Train. Dominoes are placed by matching the number of dots on one end.
Place 91 dominoes face down and shuffle. Place the train turntable in the center of the table and give each player a colored train, reserving the black one for the Mexican train. The mini trains sit on the edge of the turntable until they are needed. With 2 to 4 players, each chooses 15 box cars from the shuffled dominoes (the train yard); 5 to 6 players choose 11; 7 to 8 players choose 8.
The player with the highest double domino places it in the center of the turntable as the "Engine." Then starting with this player and moving clockwise, each player tries to begin their train by matching another domino to the engine. If no domino can be placed on the player's train or the Mexican train, that player must pick from the train yard.
The Mexican Train
This train is always an option for placing a domino if you are unable to place one on your own train. When you place a box car on the Mexican Train, you shout out "Whoo Whoo!" like a train whistle.
A player unable to place a box car on his turn picks a new box car from the yard and then moves his mini train to the end of his box cars, signaling the other players they may place cars on his train during their turns. When this player is able to place a car again, his mini train returns to the turntable.
A double domino is placed sideways when played, and that player must immediately place a second domino matching the double below it. If she is unable to, she draws a new domino from the yard. If this domino matches, it is placed and her turn ends. If not, the player moves her mini train to the double domino. The next player must now complete this double with a match or also pick from the yarn, and this continues until the double is matched.