Start with the highest double in the dealt hands
A double-six set contains 28 different tiles, with each half showing a value from zero to six. Each player receives seven tiles; the remaining fourteen form the stock. Zero is a matching value just like any other, even though its half is blank.
The highest double held by either player opens the game. A double has the same value on both halves, such as 4–4. The opening tile is selected from the dealt hands, so 6–6 does not have to start if it is still in the stock. If neither hand has a double, the tile with the highest total pip count opens.
Match one of the two open ends
After the opening tile, the chain has a left and a right open end. Your tile must match one of those exposed values with its touching half. If the ends show 2 and 5, a 2–6 tile can go on the 2 end, leaving 6 exposed there. The other end stays 5.
Tile orientation does not change which matches are legal. The game turns a tile into position when needed. Look at the values at the ends of the chain, rather than trying to match a tile somewhere in the middle. Every placement extends one end; it does not create a new branch.
A double still follows the matching rule
Once the game has begun, a double is playable only when its number matches an open end. Playing 1–1 on an exposed 1 leaves that end as 1. It does not grant an extra turn, open additional arms or let you ignore the other matching rules.
The website demonstration starts with 4–4, the highest double in its dealt hands. The next player adds 1–4 with its 4 touching the chain, exposing 1. White can then play 1–1 on that end. After these three placements, the two open values are 4 and 1.
Know whether to draw or pass
In block dominoes, you pass when none of your tiles matches either end. You do not take tiles from the stock. You cannot choose to pass while you have a legal placement, even if you would prefer to save that tile.
In draw dominoes, an unplayable hand must take a tile from the stock. If the new tile still gives you no legal move, draw again. As soon as your hand contains a playable tile, you must place a legal tile rather than keep drawing. Drawing itself does not switch the turn to your opponent. If the stock is empty and you still cannot match an end, pass.
Check how the game can finish
Playing your last tile wins immediately. A game can also finish with tiles still in both hands: two consecutive passes mean that neither player can continue. Compare the pips remaining in the hands; the lower total wins, and equal totals make a draw.
Count pips, not just tiles. A hand containing 0–1 and 0–2 totals three pips, while a single 5–6 totals eleven. If the game becomes blocked, the two-tile hand wins that comparison. This is why an awkward high-value tile can become costly near the end.
Choose the end that helps your remaining hand
Before placing a tile, imagine the new open values and check what you will still hold. If the ends are 2 and 5, you can place 2–5 on either end: one placement leaves two 5 ends, while the other leaves two 2 ends. A hand rich in 5s may favour the first option, though your opponent will get a turn before you play again.
A pass also gives information. In block mode, an opponent who passes cannot match either value currently exposed. Those values may be useful to remember as the chain changes. In draw mode, treat that clue more cautiously because drawing can add new values to the opponent's hand. Keep options available, but also notice when reducing your remaining pip total matters.