About

A rating is published after three rated games against the computer. Those three set a baseline from your score against the labeled opponent strengths (Beginner ~500 through Master ~2000). Later games use a standard Elo update, with a higher K for the first twenty. This is a recreational estimate for Aldercot games only. It is not issued by FIDE, US Chess, Chess.com, Lichess, or any federation, and it must not be used for official pairings, titles, or norms.

Aldercot follows commonly accepted Laws of Chess: castling, en passant, promotion, check, checkmate, stalemate, threefold repetition, the fifty-move rule, and insufficient material. The rules of chess are in the public domain. Aldercot is not affiliated with, endorsed by, or sponsored by FIDE, the United States Chess Federation, Chess.com, Lichess, the Play Magnus Group, or Apple.

© 2026 Aldercot. All rights reserved. The Aldercot name, interface, cut-paper piece drawings, rook mark, synthesized audio, Ghost of Yesterday, Messages play, and this app were drawn and written for this project. They are not copied from Wikimedia, Cburnett, Chess.com, Lichess, or any commercial set. Silhouettes follow the unprotectable Staunton idea (cross, mitre, merlons) using original geometry. Staunton as a style is not claimed as a trademark. Third-party names above belong to their owners and appear only for identification.

Aldercot includes an iMessage app. In a thread, open the app drawer and tap Aldercot. The board travels as a message: you send a move, they send one back. Games are unrated and do not change estimated Elo. Promotions become a queen. iMessage, Messages, and Apple are trademarks of Apple Inc. Aldercot is not affiliated with, endorsed by, or sponsored by Apple.

Ghost of Yesterday is an original Aldercot feature. © 2026 Aldercot. All rights reserved. After a rated game of at least a few moves, Aldercot may keep a recording of the side you played. Facing that ghost sits a translucent copy of those pieces opposite you: it follows your earlier moves while they remain legal, then continues at the same computer strength. The name, idea, interface, and implementation are original to this app. They are not copied from Chess.com, Lichess, or any other chess service. Ghost games are unrated and do not change estimated Elo.

Move sounds are generated in real time. No third-party sample libraries are used. Packs include Wood, Marble, Felt, Glass, Tide, Chime, Forge, or Silent. Chime and Forge come with Plus or Lifetime. Choose a pack in Studio.

Free play includes a single, labeled sponsored note on Home, Studio, Rating, and the game-over card. Ads never cover the board during a move, never autoplay sound or video, and never appear as full-screen interstitials. Remove ads with Aldercot Plus ($2.99 / month) or a one-time Lifetime purchase ($19) from the Plus page. If ads are still on, we may mention Plus once after about two hours of play and again after five hours — only on Home, never over a game. After about twenty-five minutes we may ask you to share the app; sharing unlocks the Solstice board and gilt piece set. After about forty minutes we may ask you to rate Aldercot; a rating on that card unlocks the Harbor board. Those notes only appear on Home, never over a game or the result card. Third-party advertising is described in Terms and Conditions.

Most boards and piece sets unlock by winning games in Studio (first at 3 wins, then 6, then about 1.5× each step). Custom square and piece colors unlock at 150 wins, from Studio. Share Aldercot for Solstice. Rate the app for Harbor. Plus or Lifetime adds the Quill and Lattice piece sets and the Chime and Forge sounds — they leave Studio if a Plus subscription expires. Lifetime keeps them.

Plus is an auto-renewing App Store subscription ($2.99 / month) until canceled in your Apple ID settings at least 24 hours before the period ends. Payment is charged to your Apple ID at confirmation. Lifetime is a one-time $19 unlock. Plus and Lifetime remove ads and unlock Quill, Lattice, Chime, and Forge. Friend codes (format AC-XXXX-XXXX-XXXX) also grant Lifetime and can be used only once — enter them on the Plus page. Restore Purchases on Plus if you reinstall or switch devices. Purchases do not change engine strength or unlock pieces.

The computer is for play at home and casual pass-and-play. Do not use Aldercot (or any engine) to cheat in rated games on other platforms. That violates those services' terms and the spirit of the game.

Aldercot is provided “as is”, without warranty of any kind, express or implied, including merchantability, fitness for a particular purpose, and non-infringement. Engine strength is approximate. Time-forfeits, draws by repetition, and evaluation are best-effort implementations of published rules.

Rules validation uses chess.js (BSD-2-Clause, © Jeff Hlywa and contributors). The app also uses React, TanStack, Vite, Tailwind CSS, Radix UI, Zustand, Recharts, Lucide, and Better Auth — each under its respective MIT, Apache, or ISC license. Type is system UI and Georgia. Open-source licenses are permissions to use those libraries, not ownership of them.