# Mahjong Solitaire - credits and notes

**The game.** Mahjong solitaire (also called Shanghai solitaire or the turtle) is a single-player
matching game played with a set of 144 mahjong tiles stacked face up in a layered pattern. A tile is
open when nothing lies on it and it can slide out to the left or the right; open pairs of identical
tiles are removed until the table is empty (won) or no open pair remains (lost). It was first written
by Brodie Lockard for the PLATO system in 1981 and made famous by Activision's Shanghai (1986),
Microsoft's Taipei (Windows Entertainment Pack, 1990, with 32,767 numbered configurations), Mahjong
Titans (Windows Vista and 7, by Oberon Games) and Microsoft Mahjong.

**This recreation** (https://mahjong-solitaire.skillsafe.ai/) is an independent browser
implementation of that game: the 144-tile set (Circles, Bamboo and Characters 1-9 x4, four Winds and
three Dragons x4, four Flowers and four Seasons x1), the exact turtle layout (87 / 36 / 16 / 4 / 1
tiles per layer), the open-tile rule, identical-kind matching with flowers matching flowers and
seasons matching seasons, hints, undo, shuffle, statistics and a classic window with a status bar.

Additions and choices that are this page's own, labelled as such on the page: every numbered game
(1 to 32767 - Taipei's count, but our own numbering, not that of any other program) is solvable by
construction (the tiles are placed in reverse, two open positions at a time; random turtle deals are
about 3 percent unsolvable); three original layouts named Pagoda, Bridge and Garden (not the layouts
of any Microsoft product); two original tile sets (Traditional and Large print; Mahjong Titans had
four) and five code-drawn backgrounds; the "Mahjong Solitaire scoring" table (10 per pair, +10 set
bonus for a pair from the same set as the previous one, hint -5, shuffle -50, undo free, time bonus
600 minus seconds at the win); Redo (Ctrl+Y); Pause (P), which hides the board as the Windows games
did when minimised; a timer; deep links such as /#12345-1; the game in progress surviving a reload;
optional short WebAudio clicks (off by default).

Everything here - the tile faces, the window dressing, the help text and the code - is original
work. The tile faces follow the traditional drawing conventions described in Wikipedia's "Mahjong
tiles" article (the multicolour 1 Circle, the bird on 1 Bamboo, blue numerals over a red wan on the
Characters, a blue frame for the White Dragon) and carry a small Latin label in the corner as Western
sets do. Nothing was copied from any Activision or Microsoft product, and this page is not affiliated
with or endorsed by Activision or Microsoft. "Shanghai" is a trademark of Activision; "Windows",
"Mahjong Titans" and "Microsoft Mahjong" are trademarks of Microsoft Corporation.

The code is released under the MIT licence; see LICENSE.txt.

References (fetched via the MediaWiki API, 2026-09-06): Wikipedia, "Mahjong solitaire" (rules, the
turtle, the 3 percent figure, shuffle/undo/scoring conventions, the names Shanghai and Taipei);
"Microsoft Mahjong" (Mahjong Titans layouts, tile sets and backgrounds; Taipei's 32,767
configurations); "Mahjong tiles" (the 144-tile set and its drawing conventions).