PUZZLES

Playable Puzzles

Daily-updating Tridem (a weekly rule arc) and CRYPTEM (a reel cipher), plus the browser-playable Labs.

Puzzle Lineup

Morning TRIDEM, noon CRYPTEM, evening Math?, plus the weekly and the monthly. Play whenever you like.

This Month

A day fills in once you solve at least one puzzle. All three games get a bold outline.

1+ solvedAll 3 solved

Stage puzzles

Daily puzzles

Weekly puzzles

Monthly puzzles

Labs — experimental puzzles

Tools

Puzzle meets YouTube

All videos →

Videos around our puzzles — the ideas and stories behind them.

"Solve This and Win $1,000" — the Mathematically Impossible Puzzle That Gripped America 140 Years Ago [15 Puzzle]

The Real Reason Loading Screens Stayed "Boring" for 20 Years — One Patent Held the Industry Hostage [Game Law]

Gomoku Is a Proven First-Player Win — Yet the Reason People Still Play It Is Brilliant [Renju/Game Design]