Chess

Chess is a two-player strategy game on an 8 × 8 board. On KachaPlay (kachaplay.com) you play it free in your browser — nothing to install — against the computer, a random opponent worldwide, or a friend you invite. This page covers the full rules we enforce, the ways to play, and a few pointers if you are new.

The board and pieces

The board is 8 × 8. White always moves first, then players alternate.
Each side has 16 pieces: eight pawns, two rooks, two knights, two bishops, a queen and a king.
Pieces move in their own ways — rooks in straight lines, bishops diagonally, the queen both, knights in an L, the king one square in any direction, pawns one square forward (two from their start) and capturing diagonally.

The rules we enforce

KachaPlay plays standard chess — every rule below is enforced by the engine:

Castling — king and rook move together when neither has moved and the path is safe.
En passant — a pawn that has just advanced two squares can be captured as if it moved one.
Promotion — a pawn reaching the far rank becomes a queen, rook, bishop or knight of your choice.
Check — when your king is attacked you must get out of check; illegal moves are rejected.

How a game ends

Checkmate — the king is in check and has no legal escape. The mating side wins.
Stalemate — the side to move has no legal move but is not in check: a draw.
Threefold repetition — the same position three times: a draw.
Fifty-move rule — fifty moves by each side with no capture or pawn move: a draw.
Insufficient material — neither side has enough pieces to force mate: a draw.

Ways to play on KachaPlay

Against the computer

Three difficulty levels — Rookie, Sensei and Master. Games against the computer are for practice: they do not change your rating and carry no coins or gems.

Online against a random opponent

Join the queue and you are matched with another player. These are the rated games — chess keeps its own rating, separate from every other game. Win, draw and loss are settled with the standard Elo formula, and online games are where coins and gems come from.

Against a friend

Create a room and share its link, or invite someone from your friends list; the invite lands in their message bell. Friend rooms are casual — they do not change your rating. Every online game can be played with no time limit, 5 minutes or 10 minutes per side.

For exactly how rating, levels, coins and gems work across the site, see How to Play.

A few tips for beginners

Open by taking the centre with a pawn and developing knights and bishops before the queen.
Castle early to tuck your king into a corner and connect your rooks.
Do not move the same piece twice in the opening unless you must.
Before every move, ask what your opponent's last move threatens.

FAQ

Is chess free to play here?

Yes — every game on KachaPlay is free in the browser, and you can start as a guest.

Does the computer cheat?

No. The computer plays with the same rules engine that judges the game; it sees only the board.

Do I need an account?

You can play as a guest with just a nickname. Registering with an email keeps your rating and progress and lets you sign in on any device.

国际象棋（中文）

国际象棋是 8 × 8 棋盘上的双人策略棋。在 KachaPlay（kachaplay.com）打开浏览器即可免费对弈，无需下载：可以和电脑、全球随机对手，或你邀请的好友对战。本节说明我们采用的完整规则、对战方式，以及给新手的几点建议。

棋盘与棋子

棋盘 8 × 8，白方先行，双方轮流走子。
每方 16 枚棋子：8 兵、2 车、2 马、2 象、1 后、1 王。
各子走法不同——车走直线，象走斜线，后兼两者，马走“日”，王每步一格，兵向前一格（首步可两格）、斜吃。

我们采用的规则

KachaPlay 采用标准国际象棋规则，以下均由引擎强制执行：

王车易位——王与车在均未移动且路径安全时一并移动。
吃过路兵——刚走两格的兵可被当作只走一格来吃。
兵的升变——兵抵达底线，可升为后、车、象或马。
将军——王被攻击时必须应将，非法着法一律被拒。

如何结束

将杀——王被将且无合法应着，将杀方获胜。
逼和——轮到的一方无合法着法但未被将：和棋。
三次重复——同一局面出现三次：和棋。
五十步规则——连续五十回合无吃子、无进兵：和棋。
子力不足——双方均无法完成将杀：和棋。

在 KachaPlay 的三种对战方式

人机对战：三个难度（Rookie / Sensei / Master）。人机对局仅供练习，不影响积分，也不产出金币或钻石。

在线随机对战：进入匹配队列与他人配对。这是计积分的对局——国际象棋有独立于其他游戏的积分，胜/和/负按标准 Elo 结算；金币与钻石也来自在线对局。

好友对战：建房分享链接，或从好友列表发出邀请（邀请会出现在对方的消息铃铛里）。好友房为休闲局，不计积分。每局在线对战可选不限时、每方 5 分钟或 10 分钟。

积分、等级、金币与钻石在全站如何计算，详见玩法说明。

新手建议

开局用兵抢占中心，先出马象再动后。
尽早王车易位，把王藏进角落并连通双车。
开局阶段非必要不重复走同一枚子。
每步之前先问：对手上一步在威胁什么。

常见问题

这里的国际象棋免费吗？免费——KachaPlay 所有游戏都可在浏览器免费玩，游客身份即可开始。

电脑会作弊吗？不会。电脑与裁决棋局用的是同一套规则引擎，它只看得到棋盘。