CBG -- Clavierhaus BackGammon

The first standalone backgammon app on F-Droid: a full-strength engine in your pocket, not an online client. No server, no account, no internet -- just you and one of the strongest backgammon players ever written.

CBG (Clavierhaus Backgammon) puts the real GNU Backgammon engine -- the same neural-net player and analyser that runs on the desktop -- behind a modern touch interface. It works entirely offline and contains no advertising, no analytics, and no proprietary online services.

Play

Play complete matches against GNU Backgammon at seven strength levels, from Beginner to Grandmaster. Match play includes the doubling cube, resignations, Crawford, Jacoby, automatic doubles, beavers and selectable match-equity tables.

Train

Turn on the Coach and have GNU Backgammon judge every move you make. See at a glance whether a move was the best, merely acceptable, or an error -- with the stronger alternatives and exactly what each one was worth. Tap any alternative to watch it play out on the board, arrow by arrow, against your own.

Analyse

Paste a GNU Backgammon Position ID, Match ID or XGID -- from a forum, a book, or another app. With dice entered, the engine ranks the available checker plays. Without dice, it analyses the cube decision.

Review

Save matches in GNU Backgammon's SGF format and step through them by game and move: the move you played, the engine's preferred move, the equity cost, and its assessment.

One principle underlies all of it: GNU Backgammon is the sole authority for the rules, the legal moves, the cube decisions and the analysis. The interface shows you the engine's own judgement and sends your actions to the engine -- it never substitutes its own backgammon logic. Every number you see is the engine's.

Features:

* Fully offline -- no network, no accounts, no ads, no tracking
* The real GNU Backgammon neural-net engine
* Seven opponent strengths, Beginner to Grandmaster
* Full match play with the doubling cube
* Live move-by-move coaching with equity costs
* Position analysis from GNU BG IDs and XGIDs
* SGF match saving and review
* Multiple board themes, phone and tablet layouts
* Tap, drag, and tap-a-destination checker input

Requires Android 12 or newer and a 64-bit ARM device.