#️⃣ 超级井字棋Ultimate Tic-Tac-Toe
在线超级井字棋（九宫格嵌套井字棋）人机对战：你落子的位置决定对手下一步必须下在哪个小棋盘，赢下三个小棋盘连成一线获胜；蒙特卡洛搜索电脑三档难度，可双人对战、悔棋。Play ultimate tic-tac-toe online: nine small boards inside a big one, and the cell you pick sends your opponent to that board. Win three small boards in a row. Three Monte-Carlo computer levels, two-player mode and undo.
黄色高亮的是你这一步可以下的小棋盘，点击其中的空格落子。键盘：方向键在 9×9 格子间移动，回车 落子，U 悔棋。Highlighted boards are where you may play; click an empty cell there. Keyboard: arrows move over the 9×9 cells, Enter plays, U undo.
玩法说明与常见问题How to play & FAQ
「超级井字棋」怎么玩？How do I play Ultimate Tic-Tac-Toe?
大棋盘由 9 个小井字棋盘组成。你在小棋盘里下的位置（例如右上角），决定了对手下一步必须下在大棋盘的哪个小棋盘（右上角那个）。在小棋盘里连成三子就赢下这个小棋盘；如果被指定的小棋盘已经结束，对手可以任选一个未结束的小棋盘。先赢下三个连成一线的小棋盘者获胜。The big board holds nine small tic-tac-toe boards. The cell you choose inside a small board (say, top-right) sends your opponent to the matching small board (the top-right one). Three in a row inside a small board wins it; if the target board is already decided, your opponent may play in any open board. Win three small boards in a line to win the game.
和普通井字棋有什么不同？How is it different from ordinary tic-tac-toe?
普通井字棋双方都不犯错必然平局；超级井字棋每一步都要考虑把对手“送”到哪个小棋盘，策略深得多。Ordinary tic-tac-toe is always a draw with good play; here every move also decides where your opponent must play next, which makes it far deeper.
电脑是怎么思考的？How does the computer think?
电脑使用蒙特卡洛树搜索：在后台快速模拟成千上万局随机对局来评估每一步，难度越高思考时间越长，页面不会卡顿。It uses Monte-Carlo tree search, playing thousands of quick random games in the background to rate each move; higher levels think longer without freezing the page.
小棋盘下满了没人赢怎么办？What if a small board fills up with no winner?
该小棋盘算作平局，不属于任何一方；被送到这个小棋盘的玩家可以任选其他小棋盘落子。所有小棋盘都结束仍无人三连则整局平局。It counts for nobody, and a player sent there may play in any open board. If every board is decided with no line of three, the game is drawn.
「超级井字棋」免费吗？需要下载吗？Is Ultimate Tic-Tac-Toe free? Do I need to download anything?
完全免费，无需注册、下载或安装，打开网页就能玩，手机、平板和电脑都支持；游戏完全在你的浏览器本地运行，不会上传任何数据。It is completely free with no sign-up, download or install — just open the page on a phone, tablet or computer. The game runs entirely in your browser and nothing is uploaded.