How to Play Avalanche — Collapse the Cube Block by Block

Cubedoku Guides · Published 2026-06-10

Avalanche answers a question most puzzle games never ask: what if finishing part of a Sudoku made that part disappear? It takes Cubedoku's 3D cube, splits it into small sub-cubes, and rewards you with a satisfying collapse every time you complete one — Sudoku logic with the moment-to-moment payoff of a match-3 game.

The rules

An Avalanche puzzle is a large cube — 6³ or 9³ — built from independent 3³ sub-cubes. A 6³ cube contains eight of them (2×2×2); a 9³ cube contains twenty-seven (3×3×3).

  • Each sub-cube is its own small puzzle: every visible face of the sub-cube must contain the digits 1–9 exactly once, and blocks shared between two or three faces of the sub-cube hold a single value that must be legal on all of them — exactly the rules of the 3³ size of The Cube.
  • Sub-cubes are independent: digits in one never constrain digits in another. The interaction between them is spatial, not logical.
  • The moment a sub-cube is completely and correctly filled, it collapses — it fades out and vanishes from the cube.
  • You win when every sub-cube has been eliminated.

Why the collapse changes everything

Here is the strategic heart of the mode: at the start, only the outside of the big cube is visible. The sub-cubes buried behind and inside show you only a few faces — or none at all. When an outer sub-cube collapses, it uncovers the faces of its neighbours, revealing new clues and new fillable cells.

So Avalanche is really a puzzle about excavation order. You are not just solving eight or twenty-seven small Sudokus; you are deciding which ones to finish first so that the information you need next gets exposed. The name is earned: a single collapse often cascades, as newly revealed clues let you finish a second sub-cube, which reveals a third.

Strategy for new players

  1. Count exposed faces. Corner sub-cubes of the big cube show three faces, edge sub-cubes two, face-centre sub-cubes one. More visible faces means more clues and more shared blocks to reason with — corners are almost always the right place to start.
  2. Finish, don't graze. In ordinary Sudoku it is fine to place easy digits all over the grid. In Avalanche, ninety percent of a sub-cube earns you nothing — the reveal only happens at one hundred percent. Concentrate force on one sub-cube at a time.
  3. Think one collapse ahead. Before choosing which sub-cube to attack, ask what its collapse will expose. Opening up a buried neighbour that currently shows zero faces is usually worth more than the easiest available finish.
  4. Rotate constantly. The far side of the cube is playable too. The most common beginner mistake is solving only the three faces pointing at the camera.

Choosing your size

Start with 6³: eight sub-cubes, one layer of excavation, games short enough for a lunch break. 9³ is the full experience — twenty-seven sub-cubes including a completely hidden centre one, demanding real planning about excavation routes. Both sizes come in all four difficulties, and both have Daily Challenge puzzles shared by every player worldwide.

Who Avalanche is for

Avalanche is the most arcade-like of Cubedoku's modes, and the one new players most often describe as “moreish”. The frequent collapse payoffs make it a great fit for players who find a full 9³ Cube intimidating — you get the same 3D reasoning in bite-sized, constantly rewarding pieces. If you enjoy the spatial side, graduate to The Cube; if you want pressure instead of excavation, try Blitz.

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