Dominosa Solving Tips
Dominosa is a counting puzzle: every domino has to be somewhere, and the trick is finding where it can only be. New here? Read the rules first.
1. Pairs that occur once
If 6 and 0 are neighbours in only one place, that's the 6-0 domino. Scan the grid pair by pair; the big sets hide several of these.
2. Squares with one free neighbour
A corner square has two neighbours; once one is taken, the other is forced. After each placement, look at the squares around it.
3. Cross out duplicates
As soon as 2-5 is placed, every other 2 next to a 5 can be crossed out. Crosses shrink the options around them, which forces more dominoes.
4. Chains along the border
Along an edge, a run of squares often has only one way to be paired up once a single domino in it is fixed. Follow the chain to its end.
5. Count what's left
The list under the grid shows the dominoes still to place. When only a few remain, look for where each could possibly fit; usually there's just one spot.
Frequently asked questions
Where do I start a Dominosa puzzle?
Scan for a pair of numbers that appears only once as neighbours in the whole grid, such as the only place a 6 touches a 0. That domino must be there. Then look at corners and edges, where squares have few neighbours.
Last updated 2026-10-20