Brainy Lines vs Chessdoku

Highlights your 100+ levels and the "One Stroke" logic for parents and kids.

Place the given chess pieces so every row and column holds exactly one piece — and no piece threatens another. That's Chessdoku: the discipline of Sudoku, the geometry of chess. NO GUESSING, EVER Every puzzle is generated by a built-in deduction engine and verified solvable by pure logic. Stuck? The hint doesn't just drop a piece — it explains the deduction you could have made. FIVE WAYS TO PLAY - Classic — open square boards, from a gentle 4×4 to the deep end - Panorama — wide boards that bend your instincts - Fortress — frozen pawn walls cut the lines, so extra pieces fit - Command — you place the pawns, and your pieces need them - Torus — borderless boards where attacks wrap around the edges 300 levels in each mode — 1,500 puzzles in all. EVERY DAY, ONE PUZZLE A daily challenge seeded from the date, identical for every player on Earth. Keep your streak alive and share your result, spoiler-free. THINK WITH YOUR HANDS Cross off dead squares with the X tool, pencil-mark individual piece options Sudoku-style, long-press any piece to see exactly what it attacks, and let the app prove it the moment a position becomes unwinnable. FREE TO PLAY The daily challenge, the tutorial, and a generous run of free levels — including the first 100 in Classic — are free to everyone. One optional purchase unlocks all 1,500 levels and every Quick Play preset — no subscription, ever. YOURS, OFFLINE No account. No ads. No tracking. Puzzles are generated on your device and your progress never leaves it. Seventeen handcrafted board themes, including a colorblind-friendly high-contrast set.