For grown-ups

What LatticeForge builds

LatticeForge is a guild of number-logic puzzles for ages 9–14 — Sudoku today, with KenKen, Kakuro, Nonogram, Futoshiki, Hitori, Skyscrapers, Slitherlink, and Star Battle on the way. The through-line is deductive reasoning: every grid hides one rule, and the fun is finding the cell that's forced — no guessing. A Concepts layer explains the reasoning behind each rule.

Every puzzle is guaranteed to have exactly one solution (checked by a solver), so there's always a logical path to the answer.

No pressure

There's no timer by default and no "wrong" — a number that clashes with its row, column, or box is gently flagged so it can be changed, and finishing a grid is always the win.

Our privacy promise

LatticeForge Play is free, works offline, and collects nothing. No accounts, no ads, no tracking; progress lives only in this browser.