This is a variation on the standard Draw game played for a pool of chips instead of a score. Within this game, there are all the possible versions of the Draw game.
The game uses a double six domino set, but other sets can also be used when you have more players. Players will also need some poker chips.
The size of the hand varies with the number of players:
At the start of each round, all the players put an equal stake into a pool, usually three chips. The players draw for the lead and take turns placing tiles on either end of the train. Doubles are played across the line, but are not spinners.
If a player cannot play, he can either pass or buy tiles from the boneyard. He can buy as many tiles as he wishes, each tile costs one chip. If the boneyard down to two tiles, then nobody can buy further tiles.
When the boneyard is reduced to two tiles, the player who follows the player who bought the tiles that caused the boneyard to be reduced to two tiles becomes the auctioneer and announces that the last two tiles are on auction.
Starting with the auctioneer, each player bids on the last two tiles. Bids go around the table twice (i.e. each player gets to make two bids) and the highest bid gets the last two tiles and has to put the amount of his bid into the pool. A bid can be for zero (announced as "check") or more chips, but each bid must be larger than the bid before it.
If nobody bids on the last two tiles, then they stay in the boneyard and are not used in the round.
The hand stops when one player dominoes or when nobody can play. The lead then passes to the next player in turn for the next round.
The player who dominoes wins the pool. If the game blocked, then each player totals the number of pips in his hands. The player with the lowest total is the winner and collects the entire pool. If there is a tie for lowest total, then the pool is split equally among the winning players. Any odd amount is left in the pool for the next round.
See the basic Draw game for variations in the hands, and other features of the game.
A common variation is not to have an auction for the last two tiles and simply leave them in the boneyard. This game is called Domino Pool in England.
The best play is to play your strongest suit, preferably with a double, so that you will have more options for further plays when it is your turn again. The better control you have of a suit, the more you should try to leave that suit on the ends of the train.
Do not to get carried away with buying tiles and do not go nuts at the auction. You can pay out a lot of chips and stick yourself with a large hand that will lose the round for you.
On the other hand, if you can count the suits on the table, you can buy tiles to prevent other players from getting them and lock them out of play while you take control.