What is Morpion Solitaire?
Morpion Solitaire is a single-player pencil-and-paper game played on a grid of dots. Starting from a cross-shaped pattern of 36 dots, you repeatedly place one new dot and draw a straight line through five consecutive dots — horizontal, vertical, or diagonal. Every move must create a brand-new line; the game ends when no legal move remains. The aim is simply to make as many moves as possible.
The four standard variants
Variants differ by line length (5 or 4 dots) and by whether two parallel lines may share a point: Touching (T) allows it, Disjoint (D) does not.
| Variant | Line | Overlap | Best known |
|---|---|---|---|
| 5T | 5 dots | Touching | 178 (world record) |
| 5D | 5 dots | Disjoint | 82 |
| 4T | 4 dots | Touching | 62 (proven optimal) |
| 4D | 4 dots | Disjoint | 35 (proven optimal) |
What you can do here
- Play all four variants directly in the browser — no install, multi-threaded WebAssembly.
- Hunt records with several search engines: NRPA, large-neighbourhood perturbation, and exhaustive search.
- Read, write, import, and export the self-describing MSR record format (a successor to Pentasol).
- Free and open source — the app is GPL-3.0-or-later; the msr format library is MIT OR Apache-2.0.
Frequently asked questions
- Can I play Morpion Solitaire online?
- Yes. You can play all four standard variants directly in your browser, with nothing to install.
- What is the Morpion Solitaire world record?
- The best known 5T score is 178 moves. The 4T (62) and 4D (35) variants have been proven optimal.
- Is it free?
- Yes. It is free and open source. The app is licensed GPL-3.0-or-later and the MSR format library is MIT OR Apache-2.0.
- What is the MSR format?
- MSR is a self-describing record format for Morpion Solitaire games, designed to supersede Pentasol. Its specification is published on this site.