How to play Mahjong Cube

Mahjong Cube takes the matching game into three dimensions. The tiles form a solid cube instead of a flat pile, and you turn the cube in your hands to find pairs on every side.

A Mahjong Cube game: a small cube of ivory tiles, four tiles along each edge — The small cube: four tiles along each edge, 64 tiles in all.

The goal

Take the whole cube apart in matching pairs. Every tile has to go.

Which tiles can be taken

Each tile in the cube is a small cube itself, with six sides. A tile can be taken when two of its sides that meet at an edge are open: any two open sides that aren't opposite each other, such as the top and the front. Two open sides facing opposite ways, like the top and the bottom, aren't enough.

On a full cube, the corners and edges can be taken first. Tiles in the middle of a face have only one open side until their neighbours go.

Tiles that can't be taken are drawn slightly dimmed, so the ones you can take stand out. As pairs come away, the tiles underneath open up and the cube gets smaller, layer by layer.

The tiles

The cube uses the same tiles as the other games. Each tile matches only its identical twin. The faces are printed on every side of each tile, so a tile reads the same whichever way the cube is turned.

Bamboo, 2 to 9 10 points a tile
Dots, 1 to 9 10 points a tile
Characters, 1 to 9 10 points a tile
Dragons and the peacock 20 points a tile
Winds 40 points a tile
Flowers 40 points a tile
Seasons 40 points a tile

Playing on Mahjong Haus

Choose Mahjong Cube in the settings (the gear in the top bar), and a size: small (4×4×4, 64 tiles) or large (6×6×6, 216 tiles).
Choose a stone and a face on the Stone and Face card, and a background.
Turn the cube. Drag to turn it. Pinch, or use the mouse wheel, to zoom.
Take a pair. Tap a tile you can take, then its twin, which may be on another side: turn the cube to find it.
Use the tools under the cube: undo and redo, a hint, shuffle, the demo, and pause.

Scoring

The cube is scored like the other games: points for every tile, pace and speed bonuses, and finish bonuses (including the no-shuffle bonus) when you clear it inside five minutes. Each size has its own leaderboard. See how scoring works.

Tips

Turn the cube often. A tile's twin is just as likely to be on the far side. Take a full turn around before deciding you're stuck.
Work from the corners in. Corners and edges open first. Taking them evenly, rather than digging a hole in one face, keeps more tiles available.
Don't strand the last of a kind. Before taking a pair, check where the other two tiles of that kind are. If one sits deep in the middle, keep a way open to it.
Start small. The small cube is quick to learn on; the large one hides 64 tiles inside it, out of sight until the outer layers come away.

Questions

Why can't I take a tile that's open on two sides?: The two open sides must meet at an edge. A tile open only on opposite sides, such as its left and right with its top, bottom, front and back covered, has to wait until one of those others opens.
Can every cube be cleared?: With Guaranteed winnable path on, yes: the cube is dealt so there's a way through, though a wrong order can still leave you stuck. Undo, or shuffle the tiles left.
Is there a quick way to see the rules while playing?: When a cube game starts, a short note explains how to turn the cube and which tiles can be taken, until you tick "Don't show again". The ⓘ next to the game in the settings shows the rule too.