Strategy & Tips

1. Start with the most constrained region

An “all equal” region or a small target sum usually has only one or two legal dominoes. Nail those down first — they cascade into forced moves everywhere else. Never start in a blank, rule-free region; it tells you nothing.

This is not a matter of taste. Measured properly, an all-equal region of three cells accepts7 value combinations; a rule-free region of the same size accepts343. Starting where the choices are fewest eliminates roughly fifty times more of the search space per tile.

2. Count your pip supply

Before placing anything, total the pips your tray offers against what the sum-regions demand. If the board needs a lot of high numbers, your doubles (5–5, 6–6) are precious — do not waste them in a low region.

The reverse works too. A “< 4” region on three cells can only take values that total three or less, which on a double-six set means almost every tile in your tray is illegal there. Finding what cannot go somewhere is usually faster than finding what can.

3. Use “not equal” to eliminate

A “≠” region is a gift: it removes whole classes of dominoes at once. Any double is immediately illegal inside it, so on the Hard board an early ≠ often forces your 6–6 into one specific corner — exactly the pivot the puzzle is built around.

4. Backtrack early, not late

The moment a placement breaks a rule, undo it — do not build three tiles on a shaky foundation. Good Pips solving is fast trial-and-error with quick rejection, which is exactly how our Solver works: it checks the affected region after every single half-tile and abandons the branch immediately.

5. Practise the patterns

The Hard board reuses a handful of shapes: the overlap pivot, the forced double, the low-sum corner. Play a few unlimited boards and you will start recognising them on sight.

The numbers behind rule 1

Here is how many pip combinations a three-cell region can legally hold, by rule type. Fewer combinations means the region gives way sooner — and this is the exact ranking our hint generator uses when it decides which region to point you at first.