# playbackgammon.app — full summary

Canonical URL: https://playbackgammon.app
Publisher: playbackgammon.app (contact: malam169@gmail.com)
Last updated: 2026-09-23

## What it is

playbackgammon.app is a free, 100% client-side browser game of backgammon. You play the ivory checkers against the computer's red checkers. There is no backend, no account, no download, and no real-money play. Gameplay, the computer opponent, and saved statistics all run in the browser.

Backgammon is a two-player race game on a board of 24 triangular points. Each side has 15 checkers. On each turn a player rolls two dice and moves checkers toward their own home board, hitting lone opposing checkers along the way. When all 15 of a player's checkers are in the home board they may be borne off; the first player to bear off all 15 wins.

## Rules as implemented

Setup, from the human player's perspective (points numbered 1–24; the human moves from 24 down toward 1 and bears off past 1): 2 checkers on the 24-point, 5 on the 13-point, 3 on the 8-point, and 5 on the 6-point. The computer's checkers mirror this layout.

Opening: each side rolls one die. The higher die wins the first move and plays both numbers. Ties are re-rolled.

Moving: each die is a separate move for one checker. Doubles give four moves of that number. A point holding two or more opposing checkers is blocked. Empty points, points with the player's own checkers, and points with exactly one opposing checker are open.

Hitting and the bar: landing on a single opposing checker (a blot) hits it and puts it on the bar. A player with any checker on the bar must enter it into the opponent's home board (with die value d, onto the opponent's d-point) before moving any other checker; a blocked entry point means that die cannot enter. If no die can be played, the turn is forfeited.

Forced play: if a legal way to play both dice (or all four on doubles) exists, it must be used. If only one die of a non-double roll can be played, the larger die must be played when either is possible. The interface enforces this and highlights only legal moves.

Bearing off: allowed once all 15 checkers are in the home board (points 1–6 for the human). A die equal to a point number removes a checker from that point. If a die is higher than the farthest-back occupied point, a checker may be removed from the highest occupied point.

Winning and scoring: the first player to bear off 15 checkers wins. A normal win is 1 point. A gammon (the loser has borne off no checkers) is 2 points. A backgammon (the loser has borne off none and still has a checker on the bar or in the winner's home board) is 3 points. There is no doubling cube.

## The computer opponent

For every roll the computer generates every legal complete play of its dice and scores the resulting positions with a heuristic evaluator that considers the pip count (race), checkers borne off, checkers on the bar, made points, consecutive points (primes), stacked points, and blots weighted by their exposure to direct and indirect shots. Expert always plays the top-scoring result. Casual chooses among the top few results with added randomness. It is not a neural-network engine and does not use a doubling cube. Dice for both sides come from the browser's pseudo-random generator.

## Controls

- Mouse / touch: click or tap Roll, then a checker (gold dashed ring = it has a legal move), then a highlighted destination point. Click the bar to enter a hit checker; click the tray on the right to bear off.
- Double-click / double-tap a checker: plays it with the larger legal die.
- Keyboard: R or Space roll; U undo the last move this turn; H highlight a suggested move; N new game after one ends; M mute. Board points, the bar, the tray, and buttons are focusable and respond to Enter/Space.
- Undo is available within the current turn until the turn ends automatically after the last legal die is played.

## HUD and progress

The HUD shows pip counts (the total distance each side must still travel; lower is ahead), checkers borne off, current win streak, and win rate. A status line announces rolls, hits, and results. The sound toggle (M) persists. Statistics stored on the device, separately for Casual and Expert: games played, games won, gammon-or-better wins, points won, fewest of your own turns in a win, current streak, and longest streak. Resigning a game in progress counts as a loss. Stats can be reset from the Stats panel.

## Accessibility

Explicit aria labels on the board, every point, the bar, the bear-off tray, and all buttons; a polite live region for game status; keyboard shortcuts; visible focus styling; reduced-motion support; a dark high-contrast theme designed for WCAG AA contrast.

## Site pages

- https://playbackgammon.app/ — play, plus overview, how-to, and FAQ teasers
- https://playbackgammon.app/how-to-play — full rules, controls, opponents, mistakes
- https://playbackgammon.app/tips — strategy: points, blots, primes, anchors, the race
- https://playbackgammon.app/faq — frequently asked questions
- https://playbackgammon.app/about — history, design choices, contact
- https://playbackgammon.app/privacy and https://playbackgammon.app/terms — legal