Regex Chess
Shares rank 4 of 5 chess engines by recommenders
Recommended as a novel demo: a chess engine built from 84,688 regular expressions that generates legal moves. Caveat: it plays badly and can lose on one illegal move.
Recommended as a novel demo: a chess engine built from 84,688 regular expressions that generates legal moves. Caveat: it plays badly and can lose on one illegal move.
9 people gave an opinion
- recommend it
- 5
- criticize it
- 4
- approval share
- 56%
Recommended in 1 of 13 months
- November 2025: not recommended
- December 2025: not recommended
- January 2026: not recommended
- February 2026: not recommended
- March 2026: not recommended
- April 2026: not recommended
- May 2026: recommended
- June 2026: not recommended
- July 2026: not recommended
- August 2026: not recommended
- September 2026: not recommended
- October 2026: not recommended
- November 2026: not recommended (month in progress)
Why it doesn’t carry the badge
- 5 people recommend itNeeds 10 or more, not met.
- 1.2 recommenders for every criticNeeds 2 to 1 or better, not met.
- Recommended in 1 of 13 monthsNeeds 4 or more, not met.
The same three rules apply to every product, and the badge can’t be bought. How the badge works
What people say about it
The reasons people give, with the number of comments that give each one. Open a reason to read what they said.
Why people recommend it
Each mark is one comment
Impressive, novel regex-only chess engine
“it's playing really bad, but it could be worse and it's already super impressive that it can even generate legal moves”
Comment from 19 May 2026 in “Regex Chess: A 2-ply minimax chess engine in 84,688 regular expressions” “Brilliant. The Chinese room thought experiment as a chess engine.”
Comment from 19 May 2026 in “Regex Chess: A 2-ply minimax chess engine in 84,688 regular expressions” “This is amazing. I'm at loss for words.”
Comment from 19 May 2026 in “Regex Chess: A 2-ply minimax chess engine in 84,688 regular expressions”
What people warn about
Each mark is one comment
Rejects valid moves; loses on illegal move
“I get "illegal move, game over" like 50% of the time, chrome on android.”
Comment from 19 May 2026 in “Regex Chess: A 2-ply minimax chess engine in 84,688 regular expressions” “one illegal move attempt means you just lose? That's harsh...”
Comment from 19 May 2026 in “Regex Chess: A 2-ply minimax chess engine in 84,688 regular expressions” “A little disappointed, since it's of course a valid move.”
Comment from 19 May 2026 in “Regex Chess: A 2-ply minimax chess engine in 84,688 regular expressions” Plays badly, misses mate in one
“it's playing really bad, but it could be worse and it's already super impressive that it can even generate legal moves”
Comment from 19 May 2026 in “Regex Chess: A 2-ply minimax chess engine in 84,688 regular expressions” “the computer did not act to prevent checkmate in 1”
Comment from 19 May 2026 in “Regex Chess: A 2-ply minimax chess engine in 84,688 regular expressions”
Other chess engines people recommend
The four most recommended other chess engines, with the same counts for each, so you can compare like for like. The tick on each bar marks the 2 to 1 line the badge needs.
| Product | Recommend | Criticize | Approval | Months | Owned | Badge |
|---|---|---|---|---|---|---|
| Stockfish | 47 | 8 | 85% | 9 | — | Approved |
| Sameshi chess engine | 10 | 3 | 77% | 1 | — | — |
| Chessmaster 3000 | 6 | 0 | 100% | 3 | — | — |
| Regex ChessThis page | 5 | 4 | 56% | 1 | — | — |
| Leela Chess Zero | 5 | 0 | 100% | 4 | — | — |
What people said
All 9 comments that mention it, newest first. Each links to the original comment.
“It’s very picky about how you specify a move.”
“one illegal move attempt means you just lose? That's harsh...”
“I'm not sure in which aspect it is an achievement, considering the loop isn't a regex.”
“A little disappointed, since it's of course a valid move.”
“it's playing really bad, but it could be worse and it's already super impressive that it can even generate legal moves”
“Brilliant. The Chinese room thought experiment as a chess engine.”
“I get "illegal move, game over" like 50% of the time, chrome on android.”
“This is amazing. I'm at loss for words.”
“the computer did not act to prevent checkmate in 1”
Counts come from 1,795,640 Hacker News comments, November 2025 to November 2026. How we count. Report a mistake.