Questions, answered.

It’s backgammon with a coach built in. Play full games against the computer, take on friends online, or learn with short lessons, puzzles and a position of the day. The coach doesn’t just show you the best move: it tells you why.

Yes. Tell the app you’re new and you’ll start with five short lessons on a real board: moving, doubles, hitting, coming back in from the bar and bearing off. Then you play a guided first game against a gentle coach. You can undo your moves, and your rating isn’t at stake. The first lesson takes about two minutes.

For a rule that often surprises new players, try both orders of a 6–1 and see why only one works.

We doubt it. One calibration game against the Medium coach sets your starting rating from the quality of your decisions, not the luck of the dice. After that, Expert offers a demanding computer opponent, and the Adventure ends with the match-play cube decisions that trip up club players.

Nothing. No ads, no subscription, no coins to buy.

On iPhone, from the App Store.

Three things:

• During the game, tap Hint and the coach shows you its move with arrows on the board, plus a short reason why.
• Before a costly mistake, it asks once if you’re sure. The final call is always yours.
• After the game, it walks you through your key decisions: what you played, what it would have played, what the difference cost you, and the idea behind it.

No. The coach says hello once per game and answers whenever you ask. Otherwise it only speaks up now and then: to praise a move it would have played too, or to flag a decision worth a second look after the game. Then it stays quiet for a few turns.

In plain words, based on the position in front of you: the pip count, which points matter, how many of the 36 rolls hit a blot, and what plan the position calls for. A typical line: “that turn left 11 of 36 rolls hitting you.” The numbers serious players use (equity, PR) are there if you want them, but they’re never the whole explanation.

Try reading the pip count, then explore the five main game plans on the app’s boards.

Why a move that wins less often can still lose fewer points. Compare comeback chances with gammon and backgammon risks.

PR stands for Performance Rating: the average cost of your decisions, on a scale where 0 means no measured loss against the engine’s reference. Lower is better, and lucky dice can’t flatter it. On the app’s scale, the world’s best players come in below about 3. The review after each game shows yours.

Why better decisions can take time to show up in your results.

Our recorded development tests show competitive checker play against the GNU Backgammon settings tested. In one 1,000-game test against 2-ply, CUBE Backgammon finished 16 points ahead; in a separate later 1,000-game test against 3-ply, it finished 28 points behind. Both tests had the cube off, and their confidence intervals include zero. They do not establish superiority or equivalence, or a current professional-player rating.

A separate checker-only score of about 1.5 was measured differently from the full-match PR used to assess human players. We cannot compare those figures directly.

How strong is CUBE Backgammon’s engine? The results, human standards and limits.

In a separate development experiment, we also corrected a turn-order bug that distorted the comparison between two engine versions.

No, and that matters when you’re learning. Each level thinks differently. Easy plays like a newcomer. Medium plays carefully and keeps its blots safe. Hard anticipates more of the possible replies, like a strong club player. Expert uses the full engine and thinks harder about the difficult decisions. When you beat a level, you’ve beaten a way of playing, not found a glitch.

Our engine uses models trained on many analysed positions and checked against established references. It also builds on open-source work, including wildbg and GNU Backgammon. The aim is useful advice that keeps the game moving on your phone.

Read how the coach works, from rollouts and training a smaller model to the tradeoffs that make it practical on a phone.

We also explain why we reverted an update that chose GNU Backgammon’s moves more often: a separate test found worse move choices.

Speed, privacy and long flights. A decision takes about half a second on an iPhone, so the analysis is usually done before the dice stop rolling. Your games never leave your phone to be analysed, and everything except online play works with no signal at all.

How the coach answers quickly on your phone.

The rules engine, the coach, the explanations, the lessons and the boards are all ours. Some parts of the engine build on open-source backgammon work, and their licences come with the app.

A path of 60+ short stops across nine chapters, from your first steps to the doubling cube and match play. Each stop is one challenge: find the best move, count the shots, bear off safely, take or pass. Clear a chapter and you earn a rank, from Novice all the way to World Class.

Eight families: Backgammon Initiation, Openings (all fifteen opening rolls), Position Play, Dice & Probability, Racing & Bear-off, Contact Play, Doubling Cube and Match Play. Get one wrong and you can try again with a hint before you see the answer.

One position a day, the same for everyone. You get one go, and your first answer is the one that counts. Perfect for a friendly argument over coffee.

The doubling cube adds another set of decisions to checker play: when to double, and whether to take or pass. It gets its own chapter, its own practice games (Take or Pass, Should I Double?, The CUBE Backgammon Window) and a place in the name. Our cube article shows how one offer can change the rest of a match.

Single games or matches to 3, 5 or 7 points, with or without the doubling cube, against four coach levels. Matches use the Crawford rule.

Playing a match? See why the score can change the move you should choose.

It’s an Elo rating, and only finished games and matches change it: games against the coach, and rated games online. Lessons, puzzles and the Daily Challenge never affect it, so you can practise without any risk.

The dice in ordinary computer games come from the device’s cryptographically secure random source, with an unbiased conversion to six faces. The match sequence is fixed before the first roll. Afterwards, its recorded seed and rolls can be replayed to check that they agree. This checks consistency with the seed; it is not a full public proof of how the seed was chosen. In online games, the server rolls for both players.

How CUBE Backgammon generates its dice, what Verify checks, and a replay example to try.

Fair dice can still produce surprising streaks. Why consecutive doubles feel more common than you expect, with an experiment you can try.

Yes. There are six original boards, each drawn for a city where backgammon feels at home. Las Vegas and London are yours from the start, and you earn the other four:

You can also show pip counts and point numbers, and choose how you move your checkers: Quick, Guided or Die first.

Yes. Create a private game, choose the match length, whether to use the cube and whether it’s rated, then send the invitation link. Your friend taps it and goes straight into the game.

Yes. Tap “Play someone new” and the app looks for an opponent near your Elo who wants the same match settings.

Only to play online and back up your progress. You sign in with Apple: we receive a private identifier, never your name or email, and you choose a pseudonym. Everything else works without an account.

As little as we can. We never ask for your name, email, phone number, contacts or advertising ID, and there is no chat. If you have an account, we keep your private identifier, your pseudonym, your rating, your progress for syncing and the state of your online games.

Usage statistics are off by default. If you switch them on, we receive anonymous daily counts, with no account or device attached. If you’re signed in, the same switch also shows us a short summary of your account, such as your rating and number of matches, but never your pseudonym or sign-in identity. You can export your data or delete your account at any time in Settings, Account & cloud.

Yes. Lessons, puzzles, the Daily Challenge and games against the coach all work without a connection. Only online games and syncing need one.

English and French. The French uses the vocabulary of the Fédération Française de Backgammon (porte, videau, jan intérieur), so it reads as if a French club player wrote it.

Yes. The board is described for screen readers, pip counts included, the touch targets are large, and the app follows your iPhone’s Reduce Motion setting.