Play and score Go

Play through the root API

Go uses placement and chosen passes. The root checks bounds, occupancy, suicide and its simple-ko restriction. Two consecutive ordinary passes end the game by area count. A head-start pass is distinct and does not count as one of those two.

import {createGame,playMove,passTurn,scoreArea} from "@johnmorrisdotca/narabe";
let game = createGame({variant:"go",size:9});
game = playMove(game,{row:4,col:4});
game = playMove(game,{row:4,col:5});
console.log(scoreArea(game.board,game.settings.size));
game = passTurn(passTurn(game));
console.log(game.status,game.winner,game.winBy);

{ black: 1, white: 1 }
won white territory

Understand the score

scoreArea counts stones plus empty regions bordered by one colour. Regions touching both colours or neither count for neither. It does not identify or remove dead stones: resolve them by play before passing. White receives native komi, normally 6.5 and adjusted by head-start terms through komiFor internally. scoreArea reports raw area; the settled state's winner includes komi.

Use lower-level functions carefully

The Go entry includes applyGoMove, goLegal, walledIn, areaWinner and playGoMove. applyGoMove assumes a valid empty point and only refuses suicide with null; use goLegal for the complete placement test. groupAt expects a point occupied by a stone. playGoMove expects a known legal point. Prefer playMove for untrusted input. Ko here is immediate recapture prevention, not full positional superko.