# CH960 — Chess960 (Fischer random chess) online > CH960 (formerly Royal Shuffle) is a free Chess960 / Fischer Random > platform: play Chess960 online — in your browser or in the Android > app, nothing to install. Play a friend by link or QR code, play the > computer from any of the 960 starting positions, watch and review > games, learn from zero, solve 30,000+ engine-verified puzzles and > follow a 1000-day course. Free (GPLv3-licensed client), no ads, no > purchases, no third-party trackers in the app (how the website counts > visits: https://ch960.com/privacy). Languages: en (default), ru, es, zh, hi, ar, > pt, fr, de, ja — same paths with /{lang}/ prefix. Key facts: - Chess960: the back-rank pieces start in one of 960 arrangements; castling always ends on the classical squares (g1/c1 for White). - Every starting position has a page: https://ch960.com/sp/ (0-959; /sp/518 is the classical chess setup). - Play in the browser, no install, no account: a friend by link or QR code https://ch960.com/friend (the link /c/{id} also lets others watch the game live); the computer at a chosen level https://ch960.com/play; an endless puzzle feed https://ch960.com/flow. A finished game stays at /g/{id} for 30 days with a move-by-move engine review. Rated games and arenas are in the Android app. - Undo Chess, a rule set by Roman Morozov (the author of CH960): in a game with a friend each player may get 1-3 take-back tokens, and taking a move back hands the token to the opponent. Rules: https://ch960.com/undo-chess ; core mechanism disclosure v1.0 by Roman Morozov (7 October 2026, CC BY 4.0, DOI 10.5281/zenodo.23213404): https://ch960.com/undo-chess/core ; CH960 ruleset: https://ch960.com/undo-chess/regulation - Asymmetric (DFRC) start pairs: White and Black from different Chess960 setups. A staged Stockfish search over 460,800 representatives (one of each pair and its mirror image — a mirror image is a different position), verified to 16 billion nodes and by Berserk and Lc0; the published set of balanced pairs: https://ch960.com/asym/encyclopedia ; rating of all evaluated pairs: https://ch960.com/asym ; methodology: https://ch960.com/methodology/asym ; paper by Roman Morozov (v1.2, CC BY 4.0, DOI 10.5281/zenodo.23536049): https://ch960.com/asym/paper - Position nomenclature: each of the 960 setups belongs to one of six named families — ThroneGuard, ThroneScout, BastionGuard, BastionScout, RampartGuard, RampartScout. Glossary + machine-readable dataset: https://ch960.com/nomenclature (JSON https://ch960.com/nomenclature/sp_families.json, CSV https://ch960.com/nomenclature/sp_families.csv). - 30096 tactics puzzles, each playable in the browser: https://ch960.com/puzzles (single puzzle: /p/{id}). - 1000-day course, one lesson + puzzles per day: https://ch960.com/course (single day: /course/day/{n}). - Interactive lessons from zero: https://ch960.com/learn - Daily puzzle: https://ch960.com/daily/today - Author: Roman Morozov — https://ch960.com/author (Facebook: https://www.facebook.com/MRoman31) - Android app on Google Play: https://play.google.com/store/apps/details?id=com.ch960.game (APK for devices without Google Play: https://ch960.com/download/latest) - Source code: GPLv3-licensed; available to recipients on request (public release planned). ## Core pages - [Starting positions](https://ch960.com/sp/): facts for each of the 960 setups - [Puzzles](https://ch960.com/puzzles): themes from mate-in-1 to Chess960-specific tactics - [Learn](https://ch960.com/learn): rules, Chess960 castling, opening principles - [Course](https://ch960.com/course): the 1000-day path from beginner to club player - [Nomenclature](https://ch960.com/nomenclature): the six position families plus the Shuffle Rating, Target Rating, Mirror Twin and Key-Square Tag terms (DefinedTermSet + downloadable Dataset) - [Open data](https://ch960.com/data): downloadable datasets — position families (JSON/CSV) and 30,000+ puzzles (JSON packs), CC0 - [Methodology](https://ch960.com/methodology): how puzzles are mined and verified (Stockfish, depth >= 20, forcedness validator) - [Balance of all 960 positions](https://ch960.com/balance): the Morozov Balance Index (MBI) — how large White's opening edge is in each starting position, on a 0-100 scale. Author of the methodology: Roman Morozov. Dataset https://ch960.com/balance/sp_balance.json (and .csv), CC BY 4.0. - [MBI methodology](https://ch960.com/methodology/balance): fixed node budget, single-threaded reproducible search, self-play validation, stated limits, and a one-command re-check of any single position ## Guides (en, ru) - [Chess without opening memorization](https://ch960.com/chess-without-opening-memorization) - [Learn Chess960 from zero](https://ch960.com/learn-chess960) - [Think from move one](https://ch960.com/think-from-move-one): the project motto explained - [Castling in Chess960](https://ch960.com/chess960-castling) - [Chess960 vs classical chess](https://ch960.com/chess960-vs-classical-chess)