Full-rules chess for two people sharing one screen. No download, no account — open the page, set the phone between you or sit side by side at a laptop, and take turns as White and Black. Castling, en passant and promotion all work the way they should, and the game itself calls checkmate, stalemate, threefold repetition, the fifty-move rule and insufficient material, so nobody has to argue about the rulebook.

How to play

1. Press Play together on the title screen. White sits at the bottom of the board and moves first.
2. Tap a piece and its square turns lime. The board doesn't mark where that piece can go — no dots, no rings — so read the position the way you would over a real board and tap the square you want. Tapping another of your own pieces moves the selection there instead.
3. If the square you tap breaks the rules, a red outline flashes on it and the message line between the cards tells you why: That piece cannot move there when the piece simply doesn't move that way, or That would leave your king in check when the move itself is fine but would expose your own king. Nothing is lost — your piece stays selected and you just pick a different square.
4. Tap a legal square and the piece slides across; the turn passes. The player card with the lime border is the side to move, and every enemy piece you capture shows up as a small icon on your card. The move counter and the message line sit between the two cards.
5. When a pawn reaches the last rank, a promotion picker appears — choose a queen, rook, bishop or knight.
6. When the game ends, the result overlay shows the winner (🏆) or a draw (🤝) with the reason on one line, plus Series today — the wins, losses and draws counted while this page has been open. Hit Play again for the next game, Share result to send the score to a friend, or Title to go back.

Rules

This is standard chess, nothing simplified. If your king is attacked (check) and you have no way out, that's checkmate and you lose. If you're not in check but have no legal move at all, that's stalemate and the game is drawn. The special moves are all here:

• Pawns may advance two squares on their first move and capture diagonally only.
• En passant — when an enemy pawn advances two squares and lands right beside yours, you may capture it as if it had moved only one, but only on the very next move. When the conditions are met, tap your pawn and then the square the enemy pawn skipped over; the capture simply happens.
• Castling, kingside and queenside — allowed when neither the king nor that rook has moved, the squares between them are empty, you're not currently in check, and neither the square the king crosses nor the one it lands on is attacked. Tap the king, then the square two files across, and the rook jumps over at the same time. If any condition fails you get the red flash and That piece cannot move there.
• Promotion — a pawn reaching the far rank opens a picker for queen, rook, bishop or knight.
• King safety — you can never play a move that puts or leaves your own king in check. Try one and the game answers That would leave your king in check; the turn stays with you.

Every ending is detected automatically, and the result screen tells you which one it was:

Checkmate	The king is in check with no escape — the side that delivered it wins
Stalemate — no legal moves	Not in check, but nothing can move — draw
Insufficient material	King vs king, king plus a single knight or bishop, or only same-coloured bishops left — draw
Threefold repetition	The exact same position has appeared three times — draw
Fifty-move rule	Fifty moves with no capture and no pawn move — draw
Resigned	The player whose turn it is pressed Resign twice — the other side wins

Reading the board: the selected square is lime, the from- and to-squares of the last move stay yellow, a square you tapped illegally flashes a red outline for a moment, and when a king is in check its square glows red and a "Check!" toast pops up. Files a–h and ranks 1–8 are printed along the edges, so you can follow written notation like "e4" or "Nf3" directly. Each player card collects the enemy pieces that player has captured, drawn as a row of small icons and sorted by value — queen first, then rook, bishop and knight, then pawns — so you can see at a glance what has left the board. Next to it, the score shows who is ahead on material and by how much, as "+n" beside the leading side, counting pawn 1, knight 3, bishop 3, rook 5 and queen 9. The pieces are drawn as the app's own vector shapes rather than font glyphs, so they look identical on every phone and browser, and each move plays a short slide animation.

Four tool buttons sit under the board. Undo takes back the last move — including castling, promotion and en passant — with no limit on how often you use it; a piece captured on the undone move disappears from the card again. New game asks for confirmation if a game is in progress. Resign turns into "Really resign?" and a second press within 2.5 seconds resigns for the player whose turn it is. Face-to-face rotates the top side's pieces and Black's player card 180° so the person sitting across the table can read them normally; it's on by default on touch devices and the setting is remembered on that device.

Tips for winning

• Treat the red flash as free information. A refused tap costs nothing — no lost turn, no penalty — so when you're unsure, just try it. That would leave your king in check in particular tells you the piece you picked is pinned to your king. If your opponent keeps seeing that message, your bishops and rooks are doing their job.
• Centre first, then castle. Push a centre pawn, bring out knights and bishops, and castle by tapping the king and then the square two files over as soon as the conditions are met — tapping is the fastest way to find out. A castled king behind unmoved pawns is hard to get at.
• Let the "+n" and the captured icons guide your trades. When you're ahead on material, swap pieces and simplify — the advantage grows as the board empties. When you're behind, avoid trades and keep things messy. The rows of captured pieces on the cards show exactly what each side has lost.
• Read the yellow squares. The last move stays highlighted, so before you touch anything, ask what that piece now attacks. Most blunders come from missing the threat that was just created.
• Don't stalemate a won game. With a lone enemy king, every escape square matters. Count them before each move — if the king is about to have none and you're not giving check, change your plan. The repetition and fifty-move draws bite the same way, so make progress instead of checking forever.
• Undo is a teaching tool. If you're playing with someone learning the game, agree to take moves back and try a different line. It's unlimited, and the whole move is restored — castling and promotions included.

Frequently asked questions

Why doesn't the board show me where a piece can go?

By design — it plays like a real board. Tapping a piece only marks its square in lime; where it goes is up to you. The safety net is that an illegal tap is refused on the spot with a red flash and a one-line reason, and nothing is lost, so beginners can experiment freely. Unlike the Janggi app, which announces check but doesn't enforce it, chess here keeps the full rules: a move that leaves your king in check is never allowed.

Why can't I castle?

If you tap the king, then the square two files over, and get the red flash with That piece cannot move there, one of the conditions has failed: the king or that rook has already moved, a piece still stands between them, you're in check right now, or the square the king would cross or land on is attacked by an enemy piece. Check each in turn — most often it's a bishop or knight still sitting on its starting square.

What is en passant?

When an enemy pawn uses its two-square first move and lands directly beside one of your pawns, you may capture it as though it had only moved one square, by moving diagonally into the square it skipped over. The chance lasts exactly one move. If it's available, tap your pawn and then the skipped square; if all you get is the red flash, the moment has already passed.

How does promotion work?

Move a pawn onto the last rank and a picker opens immediately. Choose queen, rook, bishop or knight; the pawn changes on the spot and the turn passes. A queen is almost always right, but occasionally a knight gives check or a rook avoids a stalemate where a queen wouldn't.

The game ended in a draw — why?

Read the reason on the result screen. Stalemate means the side to move has no legal move but isn't in check. Insufficient material means neither side could ever deliver checkmate with what's left (king vs king, king plus one knight or bishop, or bishops all on the same colour). Threefold repetition means the same position has occurred three times. The fifty-move rule triggers after fifty moves without a capture or a pawn move. All four are standard rules and are applied automatically.

How do we play sitting across from each other on a phone?

Turn on Face-to-face in the tool bar. The top side's pieces and Black's card rotate 180° so they read correctly from the other side of the table. On touch devices it's already on, and whatever you set is remembered on that device.

Is there an online mode or a computer opponent?

No — this is two people on one device, taking turns. Use Share result after a game to send the score and a link to a friend and line up the rematch.

Good to play alongside

• Janggi · Korean Chess (2 players) — Korea's own chess with cannons and a palace, same face-to-face mode
• Gomoku (2 players) — five in a row on a 15×15 board, a game takes minutes
• Reversi · Othello (2 players) — flip discs, legal moves shown, big swings in the last few turns
• Alkkagi · Stone Flicking (2 players) — flick go stones off the board, pure reflexes
• Sudoku — for when you're on your own, with a fresh daily puzzle