TappyPotato logic puzzles

Pencil logic

Shakashaka — rules and where to play

SHAKASHAKA · Shaka Shaka / Shikaku (different type)

Drop half-cell right triangles into the grid so the remaining white space breaks into rectangles. A digit counts the triangles touching it — convoluted to describe, excellent to play.

Origin
2006 · Japan
Difficulty
★★★★★ 2–4 / 5
Time
5–30 min
Grid
8×8 – 20×20
Sites
10

Rules

  1. Place right triangles in empty cells so that the remaining white area splits into rectangles.
  2. A digit counts triangles directly adjacent to it in the four directions.
  3. Black and filled cells block the count.
  4. Every resulting white region must be a rectangle.

How to start

Clear the 0s and the corners first

Zero means no triangle in any of the four directions; corner triangles have almost one orientation.

The rectangle rule is the real test

Any fill that leaves an L-shaped white area is out.

Triangles travel in pairs

Most appear in pairs or clusters; a lone triangle usually breaks something.

Where players get stuck

  • Reading "adjacent" as "within sight" — the rule counts only the directly touching cell.
  • Allowing non-rectangular white regions, which opens the puzzle to many solutions.

Play Shakashaka

10 sites
Puzzle PicnicFree

Handmade Nikoli-style grids from a mix of setters, picked rather than dumped, playable in the page.

Open → PuzzleMixFreemium

Gareth Moore's site: Sudoku, then Slitherlink, Nurikabe, Futoshiki, Calcudoku and Hanjie.

Open → pzv.jpFree

A wider puzz.link-style database — more types, cut a bit finer.

Open → Penpa+Free

A fat editor for Japanese types: lots of shapes and marks, and it will ingest a puzz.link.

Open → pzplusFree

A community bank with difficulty and clear counts, browsable without leaving the page.

Open → Naoki InabaFree

Naoki Inaba writes a lot, including types you won't see many other places.

Open → Puzzle Square JPFree

A large Japanese variant archive that moves often, with difficulty marks on the grids.

Open → Grandmaster PuzzlesFree

Thomas Snyder's own handmade Sudoku and variants — world-champion difficulty, not generated filler.

Open → GridPuzzleFree

Dozens of grid logic types in the browser, with progress tracking and dailies.

Open → Puzzle ShakashakaFreemium

Puzzle Team Shakashaka specialty — paint black triangles to make white rectangles.

Open →

Browse Japanese pencil puzzles →

Also on multi-type portals

Janko.atFree

Otto Janko's German/English archive: hundreds of playable types, all free.

Open → Puzzle RulesFree

Clean rule pages for dozens of types. Fastest way to learn a grid you haven't seen.

Open → NoqxFree

An ASP solver for 170-plus types. Connectivity puzzles tend to come back quickly.

Open → Nikoli Puzzle SolverFree

Z3 under the hood, 100-plus types, including hex and triangle boards.

Open →

Browse portals →

Related puzzles

NumberlinkNurikabeSlitherlink
About this page
  • Last updated 2026-09-22
  • Source Curated compilation of established puzzle rules and listed third-party play sites
  • Audience Players learning Shakashaka rules or looking for online sites to play
  • Covers Rules summary, how to start, common pitfalls, and the dedicated play sites listed on this page
  • Does not cover Hosted puzzles, worked solutions, official contest rankings, third-party uptime or pricing guarantees
  • Not advice This page is puzzle reference content only. It does not constitute financial, legal, medical or other professional advice.
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