Duplex · Free in your browser
Norinori Logic Puzzle: Duplex
Shade two cells in every region. Every puzzle has exactly one solution.
The rules
- Unshaded
- Shaded
- Not decided yet
- Shade cells in a grid divided into regions.
- Two dominoes never share an edge. Touching at a corner is fine.
- Two kinds of mistake are marked as you play: a region with too many shaded cells, and a shaded cell touching two or more others. What is still missing is not marked — a region short of two, a shaded cell without its partner — so a board with no red on it is not necessarily solved.
- Tap a cell to shade it, tap again to clear it. Long-press to mark it unshaded instead. Drag to mark a run.
- Got it
- Every region holds exactly two shaded cells.
- Every shaded cell has exactly one shaded neighbour, so the shaded cells come in pairs side by side: dominoes. A domino may cross a region border.
- Every puzzle has exactly one solution.
How to play here
Three ways to play
Campaign
Chapters that start gently and bring in one new idea at a time.
Daily puzzle
A new board every day, the same for everyone. Solve every one in a month and that month's trophy is yours.
Endless
Keep going as long as you like, in Easy, Medium, Hard and Expert.
About the game
Duplex is a Norinori puzzle for players who like unhurried, honest logic. The name means "twofold", and the rule is exactly that: every region holds two.
The grid is cut into regions. Shade cells so that every region ends up with exactly two shaded cells, and so that the shaded cells come as dominoes: every shaded cell touches exactly one other shaded cell, side by side. A domino may cross a region border, but two dominoes never share an edge. Tap a cell to shade it; press and hold to mark it unshaded.
One solution, every time
Every puzzle has exactly one solution, checked by a solver before it ships. The hint button uses that same solver: it shows the next step the board allows, and says which idea it used.
Learn it by playing it
The walkthrough hands you real positions and asks for the one cell that follows, then shows you why. Five ideas carry you a long way: a region that has only two cells, a region that already has its pair, a domino that is complete, a shaded cell with only one possible partner, and a cell that can never find one.
Three ways to play, all offline
- Campaign chapters, from gentle openings to genuine work
- A daily puzzle, the same one for every player worldwide
- Endless mode in four difficulties: Easy, Medium, Hard, Expert
Measured in months, not streaks
Solve every day of a calendar month and the month earns its own trophy. There is no streak to lose: a day you missed can still be filled in from the archive.
Built to be pleasant
- Material 3 design, light and dark, following your system colours
- No account and no sign-in; your progress stays on your device
- Boards shaped for a phone held in one hand
- 27 languages
Common questions
Is Duplex free?
Yes. You can play here without paying and without an account. Ads keep the lights on.
Where is my progress saved?
In this browser, on this device. If you clear the site data, your progress goes with it. A free Solvarium account keeps it safe.
Does it work on a phone or tablet?
Yes. It runs in any current browser on phones, tablets and computers, and the board resizes to fit the screen.
Does every puzzle really have one solution?
Yes. Every board goes through a solver before it ships, and anything with more than one solution is thrown out.