sortie

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

The move limit counts your moves only. A ◆ and dashed border mark the specific capture target. Each mission is forced against every legal defence: “Capture” means take that piece; it does not promise a material gain, since the defender might recapture. A “Win” mission does claim material and says how far ahead you finish. These capture missions are about forcing the marked piece’s capture, even if that involves a sacrifice.

Every move that still forces the mission is accepted; a legal move that throws it away stays unplayed. Undo takes back a whole player/defender turn, as often as you like. Reset restarts this puzzle. 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. Progress saves on this device when storage is available, and everything plays offline.

All positions come from the Lichess open database puzzle export, dedicated under CC0 1.0 Universal (legal text). Individual authors are not supplied and no endorsement is implied. Modifications: each sourced puzzle starts after the source’s first (setup) move, and the mission, move limit, accepted alternatives and defender replies are re-derived by Sortie’s own exhaustive search; titles, hints and explanations are written for Sortie. Source identifiers and game links are listed below.

Rules use chess.js 0.10.3 by Jeff Hlywa, under the BSD 2-Clause license. The bundled copy exposes legal-move hooks so the page can verify positions locally; no remote engine or network request is used.

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