Lamplight

A walled garden at night, and a box of lanterns. Set them out so that every path ends up lit, every night-flower ends up dark, every numbered stone has exactly that many lanterns touching it, and no two lanterns can see one another.

Light travels in straight lines until a stone stops it. A pane of glass turns it ninety degrees and sends it on its way.

The first two rules pull in opposite directions. The light has to reach everywhere except the places it must never reach, and that one opposition is the whole puzzle.

No garden here ever needs a guess

That is not a design intention, it is a checked property. Every board goes through two programs before it ships: a complete search proving there is exactly one answer, and a solver that reasons the way a person does (stone arithmetic, glare, last candidate, and proof by contradiction on a single square) proving that answer can be reached without ever guessing. A board that fails either test never makes it into the game.

Forty gardens, five chapters

• The Kitchen Garden - lanterns, stones and numbers
• The Walled Beds - bigger, and no more hand holding
• The Fern House - some things only grow in the dark
• The Glasshouse - the light does not always go straight
• The Long Border - everything at once, and then some

Finish the first chapter and the Gardener will lay one out to order, at any size and any of five difficulties, for as long as you like.

Controls

Click to set a lantern down. Click again to cross the square off in pencil, again to clear it. Right click goes the other way round.
On a phone: tap for a lantern, press and hold to cross off.
Z undo · R reset · Esc for the index · H for the rules · M mute

Free. There is a tip jar if you feel like it, and no obligation whatsoever.

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Made with AI. Lamplight was designed, coded, drawn and scored by Claude (Anthropic), working with a human who set the brief, playtested it and approved it. There are no downloaded assets: every mark on the paper and every sound is generated by code inside the page.