Play Norinori Online

Norinori treats each black square as one half of a domino. Exactly two black cells must lie in every room, and each black cell must touch exactly one other black cell. A pair may cross a thick room border. That detail changes the opening move: decide which cells can pair across rooms before filling the first clue-free room.

1. Look at the four two by two rooms marked by thick borders.
2. Click an unknown square once to shade it black, again to mark white, and a third time to clear the mark.
3. Place exactly two black squares in each room.
4. For every black square, find precisely one black neighbor directly above, below, left or right.
5. Pairs may span room boundaries, but longer black chains are invalid.
6. Mark all unused cells white to complete the board.
7. Begin with the room boundaries and the global pair rule. On this four by four board, each two by two room needs two black cells. A pair may sit wholly in one room or split across a border, so a room's two black squares do not always form a pair with each other. Mark certain white cells to track the distinction.
8. Inspect the black squares one by one at the end. Every square needs exactly one side-touching black partner. A square with no partner is isolated, and one with two partners belongs to an invalid chain. Then count each room again: a valid domino across a border still gives just one black cell to either room, not two to both.

• Every room contains exactly two shaded squares.
• Every shaded square has exactly one orthogonally adjacent shaded neighbor.
• That rule divides shaded cells into two-square dominoes.
• Diagonal neighbors do not form a domino; pairs may cross a room border.
• Every black square must have exactly one black neighbor above, below, left or right. That rule excludes both isolated squares and clusters of three or more. Counting two cells per room alone does not guarantee a valid board. A domino that crosses a thick boundary contributes one shaded cell to each room it enters.

• When two black cells already form a pair, mark all their other side neighbors white.
• Room counts alone are insufficient: check whether each black cell has exactly one partner.
• A room's two cells do not need to touch each other if each finds a partner in another room.
• A line of three black cells cannot work because its middle cell has two black neighbors.
• Use an empty neighboring room to test where a boundary-crossing pair could go.

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• Room counts and domino pairing create two distinct checks.
• Pairs across boundaries reward inspecting neighboring rooms together.
• The pairing rule makes Norinori especially readable near room boundaries. A black pair creates forced white neighbors immediately, and those whites narrow the remaining placements. When every room shows two black cells, a final scan for solitary cells and three-cell chains catches errors a simple room count would miss.

Play Norinori free in your browser. Start the interactive board above, use its on-screen controls and check the rules below when a deduction gets stuck. No download or account is needed.

Try another round of Norinori on the board above. Start with the most constrained part of the grid, test each move against the stated rules, and use the reset control to try a new approach.

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