How to play Block dominoes

Block dominoes is played with a standard double-six set: twenty-eight tiles, each showing two numbers from blank to six, with every possible pairing appearing exactly once. Seven tiles carry each number, counting the double. Two players take seven tiles each and the remaining fourteen sit face down and untouched for the whole round. That last detail is what makes Block a different game from Draw: the tiles you are dealt are the tiles you will play with, so a bad hand has to be managed rather than escaped.

Setting up a round

Shuffle the set face down and deal seven tiles to each player. The player holding the highest double leads with it. If nobody was dealt a double, the heaviest tile leads instead. Play then passes to the left, or in a two-player game, back and forth.

This app places the leading tile for you, because the rule leaves no decision to make. Some house rules let the player who wins the previous round open with any tile they like. That version rewards the leader more, and it makes the opening far less predictable; we use the highest-double convention because it is the most widely recognised and because it makes a shared seed replay identically for both players.

Making a move

The line of play has exactly two open ends. On your turn you must place a tile that matches one of them: a tile showing a four can join an end showing a four, on either half. Doubles are traditionally laid across the line rather than along it, which is why they look different on the board here. That is presentation, not a rule: the double still joins one number and exposes the same number.

If you have a legal move, you must make it. You cannot choose to pass in order to hold a tile back for later, and this is worth knowing because it is the single biggest difference between how beginners think Block works and how it actually works. Passing is not a tactic; it is what happens when you are stuck.

If you have no tile matching either end, you pass, and your turn is over. In Block there is no draw pile, so a pass is final for that turn.

How a round ends

There are only two ways out of a round.

• Someone plays their last tile. This is called going out, or “domino”. The round stops immediately.
• The board blocks. Every player passes in succession, meaning nobody can move. There are still tiles in hand and no way to play them, so the round is dead.

A blocked round is common in Block and it is not a draw. The player holding the fewest pips wins it. See scoring, blocked games and the tie rule for exactly how the points are worked out, including what happens when two hands come to the same total.

What makes Block hard

Because no tiles are ever added to a hand, every pass is permanent information. If your opponent passes when the ends show a two and a five, they hold no twos and no fives, and they will never hold one. Three passes into a round, a careful player knows a great deal about what the other side is holding, and can start setting ends the opponent has already proven they cannot answer.

This is also why dumping your heavy tiles early matters so much. Every pip left in your hand when the round ends is a point for somebody else, and in Block you cannot draw your way out of a hand full of sixes. The strategy guide goes through the reasoning the Sharp opponent applies, which is the same reasoning the coach explains when you ask it for a suggestion.

A useful habit: when your opponent passes, say the two open-end numbers out loud. Those two numbers are now permanently missing from their hand, and remembering that is most of what separates a strong Block player from an average one.

Number of players

Block works with two, three, or four players. With three or four, deal five tiles each rather than seven so there is a sensible amount of the set in play. This app currently offers two-player matches against the computer; the rules engine underneath already handles more, so additional seats are a question of interface rather than logic.