TappyPotato logic puzzles

Pencil logic

Gokigen Naname — rules and where to play

GOKIGEN NANAME · Slant / Slash Puzzle / Gokigen

Each dot states how many slash ends touch it. Slashes may never form a closed loop — one rule, and it bites hard.

Origin
1992 · Japan
Difficulty
★★★★★ 2–4 / 5
Time
5–25 min
Grid
6×6 – 15×15
Sites
9

Rules

  1. Draw one diagonal slash in every cell (/ or \).
  2. At a numbered dot, exactly that many slash ends must touch it.
  3. Slashes may never form a closed loop.
  4. Unnumbered dots are unconstrained.

How to start

0s and 4s clear a zone instantly

Both kill or force all four candidate slashes around the dot.

Lean on "no loops" when logic stalls

When numbers run out, the deciding argument is almost always "this slash would close a circuit".

Work in from the border

Edge dots have fewer candidates, so the opening is nearly always on the rim.

Where players get stuck

  • Pushing only on numbers and forgetting no-closed-loop is the real engine.
  • Miscounting ends — an end is the tip of a slash touching that dot.

Play Gokigen Naname

9 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 →

Browse All-in-one portals →

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 →

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About this page
  • Last updated 2026-09-22
  • Source Curated compilation of established puzzle rules and listed third-party play sites
  • Audience Players learning Gokigen Naname 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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