rooklight

Tap your piece, then a dotted square. You play the side named below the board; the defender responds automatically. These are short tactical positions, not full matches. Standard chess rules apply, including check, castling, en passant and choosing a promotion.

The limit counts your moves only. A ◆ and dashed border follow the specific capture target. “Capture” means take that piece, regardless of a later recapture; it does not promise a material gain.

Every move that forces the mission is accepted. A legal move that loses the forced solution stays unplayed, so you can try another idea. Undo takes back an entire player/defender turn, as often as you like. Reset restarts this level. Hints reveal an idea, then a piece, then a move.

Keyboard: Tab to the board, arrow keys to explore, Enter or Space to select and move, Escape to deselect. U undoes and R resets when the board has focus.

Ten levels a day, rotating through three distinct collections (30 positions) by your local date. The finite collection repeats every three days. Progress and unfinished levels save on this device when storage is available. Gameplay works entirely offline.

Positions from the Lichess open puzzle database, dedicated under CC0 1.0 Universal (legal text). Individual authors are not supplied. No endorsement is implied. Each position applies the source's setup move; level 2 also advances two plies to isolate a direct capture. Missions, hints and explanations are written for Rooklight.

Rules use chess.js 0.10.3 by Jeff Hlywa, under the BSD 2-Clause license. The local copy exposes legal-move hooks for exhaustive verification; no remote engine is used.

Copyright (c) 2020, Jeff Hlywa (jhlywa@gmail.com)
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