What makes a Sudoku 'the hardest'?

Difficulty is best measured by the most advanced logic a puzzle forces you to use, not by how few clues it shows. SE grade is the difficulty number from Sudoku Explainer: the higher the grade, the more advanced the logic a puzzle demands. Easy puzzles sit near 1.0–2.0; the hardest monsters reach roughly 11.0 and above. The very hardest puzzles — the 'monsters' — sit around SE grade 11 and above. They offer no naked singles to start with and cannot be solved without long forcing chains, the deepest standard technique.

What are the most famous monster puzzles?

These are widely documented in the Sudoku community. Each links to its own page with the grid and full story. Arto Inkala's 2012 puzzle — SE grade 11.9 (Arto Inkala, 2012); AI Escargot — SE grade 11.0 (Arto Inkala, 2006); Easter Monster — SE grade 11.0 (JPF (forum.enjoysudoku.com), 2007).

How do I train on hard Sudoku?

Hardest Sudoku grades every puzzle on the SE grade scale and goes up to the monster bands. See how we rate difficulty or the techniques you'll need.

什麼是最難的數獨？

客觀的答案 — 以 SE 等級量表測量，而非行銷標籤。

By The Hardest Sudoku Team · Last updated 2026-06-18

TL;DR

最難的數獨謎題評分約在 SE 等級 11 以上 — 像 AI Escargot 這樣的「怪物」沒有輕鬆的切入點，非用上長強制鏈不可。以下說明這代表什麼，並介紹著名的例子。

什麼讓一道數獨成為「最難」？

衡量難度最準的方式，是看謎題強迫你使用的最高階邏輯，而不是看它顯示的已知數有多少。 SE 等級是 Sudoku Explainer 給出的難度數值：等級越高,謎題要求的邏輯越高階。簡單謎題在 1.0–2.0 附近,最難的魔王大約在 11.0 以上。

最難的那批謎題 —「怪物」— 位於 SE 等級 11 上下與更高。它們一開始沒有任何顯性唯一數可下手，非得用上最深的標準技巧「長強制鏈」才解得開。

最有名的怪物謎題有哪些？

這些謎題在數獨社群中都有詳盡記載。每一題都連到自己的頁面，附盤面與完整故事。

謎題	SE 等級	作者	年份
Arto Inkala's 2012 puzzle	11.9	Arto Inkala	2012
AI Escargot	11.0	Arto Inkala	2006
Easter Monster	11.0	JPF (forum.enjoysudoku.com)	2007

怎麼練習高難度數獨？

Hardest Sudoku 以 SE 等級量表為每道謎題評分，並一路涵蓋到怪物區間。想深入了解，請見我們如何評定難度或你將用到的技巧。

玩最難的謎題 →

資料來源：Sudoku Explainer（SE）評分；SudokuWiki.org；enjoysudoku.com 論壇（「hardest sudoku」討論串）；Arto Inkala 謎題的當時媒體報導。