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About this chess board

Unblocked Chess is a free browser-based chess game built for people who just want to open a tab and play. There is nothing to download, no account to create, no email to verify. Drop a pawn, push a queen, deliver a back-rank mate, and close the tab.

The board uses the same well-tested move logic that powers thousands of chess sites and apps. Every rule of standard chess is here: castling, en passant, pawn promotion, threefold repetition, the fifty-move rule. If a move is legal, it works. If it isn't, the piece quietly returns to its square.

The single-player AI runs locally on your device using a negamax search with alpha-beta pruning and a piece-square evaluation. Beginner plays sensibly but misses tactics on purpose so newer players can win and learn. Expert looks three moves deep and will punish loose play. Pick the level that gives you a good game today and move up when it stops being a fight.

If you'd rather play a human, switch to 2-Player mode. The board flips after every move so each player always sees their own pieces from the bottom — pass the laptop, pass the phone, pass the iPad in the back of a classroom. It works.

Frequently asked questions

How the computer opponent actually works

The engine on this page isn't a stripped-down toy that plays random legal moves. It runs a negamax search with alpha-beta pruning — the same family of algorithm that powered every serious chess program before neural networks arrived. In plain terms: it looks ahead a few moves, assumes you'll play your best reply, and picks the line that leaves it best off.

The five difficulty settings change how deep that search runs and how much randomness is injected into the evaluation. On the easiest level the engine deliberately overlooks things and will hang pieces, because an opponent that never makes a mistake is useless for a beginner trying to learn. On the hardest level it searches several moves deeper and plays the best move it finds every time. Most people find level three roughly matches a casual club player.

Everything runs in your browser. No moves are sent to a server, no account is created, and nothing about your game is stored after you close the tab.

The rules in ninety seconds

If you are here to learn rather than just to play, this is the shortest complete summary of chess that is still accurate.

The goal is checkmate: attacking the enemy king so that it cannot escape, cannot block the attack, and the attacking piece cannot be captured. You do not capture the king — the game ends the moment escape becomes impossible.

The pieces move as follows. The rook moves any distance in straight lines. The bishop moves any distance diagonally, and stays on its starting colour for the entire game. The queen combines both. The knight jumps in an L — two squares one way, one square across — and is the only piece that can leap over others. The king moves one square in any direction. Pawns move forward one square, may advance two on their first move, and capture diagonally rather than straight ahead.

Three special rules catch most beginners out. Castling moves the king two squares toward a rook while that rook jumps to the other side, provided neither has moved and the king does not cross an attacked square. En passant lets a pawn capture an enemy pawn that has just used its two-square advance to slip past. Promotion turns any pawn reaching the far rank into a queen, rook, bishop or knight — almost always a queen.

Draws happen more often than beginners expect: by stalemate, by agreement, by threefold repetition, by the fifty-move rule, or when neither side has enough material to force mate. The difference between stalemate and checkmate decides an enormous number of amateur games, usually in favour of the player who understood it.

Our complete rules reference covers every case, including the rare ones.

Five principles for your first ten moves

You do not need opening theory to play a reasonable opening. These five ideas will produce a sound position against almost anything at club level.

1. Take the centre. Pawns on e4 and d4 (or e5 and d5) control the squares your pieces need. A knight in the centre reaches eight squares; the same knight in the corner reaches two.
2. Develop knights and bishops early. Every piece still sitting on its starting square is a piece not helping you. Aim to have both knights and both bishops out before you start an attack.
3. Castle by move ten. The king is safer behind an untouched wall of pawns than in the centre, where files open and attacks land. Our guide to how castling works covers the five conditions.
4. Do not move the same piece twice. Every repeat move is a turn your opponent spends developing a new piece. Exceptions exist, but they need a concrete reason.
5. Keep the queen home for now. An early queen gets chased by knights and bishops, and every attack on her costs you a tempo while your opponent develops for free.

When you are ready for actual openings, you need two, not twenty — see our five openings for beginners.

What to do when you have no idea what to do

The middlegame is where most players freeze. There is no book move, the position looks equal, and nothing obvious presents itself. A reliable checklist:

• Check every check, capture and threat — yours first, then your opponent's. Most blunders below 1500 come from missing a reply, not from choosing the wrong plan.
• Find your worst piece and improve it. If nothing is forcing, the strongest quiet move is usually the one that activates whichever piece is doing least.
• Ask what your opponent wants. Their last move had a purpose. Working out what it was is often more useful than pursuing your own plan.
• Look at the pawn structure. Pawns cannot move backwards, so pawn moves are permanent. Open files belong to rooks; blocked positions favour knights; open positions favour bishops.

The tactical patterns worth recognising instantly are the fork, the pin, the skewer, the discovered attack, and removing the defender. Those five account for the large majority of material won in amateur games.

Where to go after your first few games

If you've just played a game or two and want to actually improve rather than just pass time, the ordering that works for most people is narrower than you'd expect:

Start with tactics, not openings. Below roughly 1500 rating, games are decided by someone missing a fork or hanging a piece — not by opening preparation. Our mate in 1 puzzles are the fastest way to build that pattern recognition, and every position on the site has been checked by an engine before publication.

Learn two openings, not twenty. One reply as White and one as Black covers almost everything you'll face. The London System and the Caro-Kann are the usual recommendation because both give you a sensible position without memorisation.

Learn three endgames. King and rook against king, king and pawn endings, and the basics of rook endings. Most amateur games reach an endgame, and most amateurs have never studied one.

New guides and articles go up regularly on the Unblocked Chess blog, and there is more about who runs this site and how the chess content gets checked on the about page.

Two ways to play here

The board at the top of this page does two things, and which one you want changes how you should set it up.

Against the computer. Five difficulty levels, from an opponent that hangs pieces on purpose to one that plays the best line it finds. We explain how the engine chooses its moves and which level to start on — and if it is beating you, how to beat it covers the specific weaknesses a shallow search has.

Two players on one device. Switch on two-player mode and pass the screen back and forth. No second account and no second device, and the board enforces every rule so nobody has to adjudicate whether castling is legal. Our guide to two-player chess on one device also covers the odds handicaps that make a game between mismatched players worth playing.

Keep going

Sharpen up between games with these guides: