About The Cartographer’s Lie
What it is
A daily logic puzzle set on a hand-engraved nautical survey chart. Each day a cartographer draws an island of about forty-eight hexes and hides one false entry in it: a single hex drawn as something it is not. You are given a handful of survey notes, and every note is true. Only one hex can satisfy all of them at once. Find it and file your correction. You get three, and a clock that starts when you turn the chart over and never pauses.
It belongs to the family of daily games that give everyone the same puzzle on the same day, but the reasoning is spatial rather than verbal. The clues are compass bearings, counts of neighbours, sheet boundaries and ground types, and they triangulate a position the way a surveyor would. Bearings are strict: north-east of a beacon means north of it and east of it, both at once.
Where and when
A new chart is drawn every day at 5am New York time, the same island for every player, in the browser and in the apps. The Casual and Standard charts are free here on the web with no account. The free iPhone and Android apps add the Hard chart, streaks, ratings and duels against friends. The Fiendish chart, unlimited extra charts and the full archive are part of the Cartographer’s Guild, an optional membership in the apps.
The game is in English, Spanish as spoken in Spain, and Spanish as spoken in Mexico. There is no advertising inside the game.
Who made it
It is made by one person, Kevin Marsh, and launched on the web and on iPhone in August 2026 and on Android in October 2026. The island generator and the solver that proves every day’s chart has exactly one answer are the same code on all three platforms.
Press and contact
For press, partnership or anything else, write to info@mieruconsulting.ai. The name, the chart artwork and the share grid are free to reproduce in coverage of the game. A plain-text summary for automated readers is at /llms.txt.