· Logic · Original
Play chess online free against a hard computer engine
A full game against the SkillX engine, which looks several moves ahead. Castling, en passant, promotion: every rule is in.
What is Chess?
A full game of chess against the SkillX engine, which looks several moves ahead. You play White. Every rule is in: castling, en passant, promotion, check, mate and draws.
SkillXGames includes a complete chess game against a computer opponent at a hard level. You play White, the engine plays Black, and every official rule is enforced: castling on both sides, en passant, promotion to any piece, check, checkmate, stalemate, threefold repetition, the 50-move rule and insufficient material.
There is no account, no ads between moves and no time control: take as long as you like to think, then see if you can beat the engine.
At a glance
- Category
- Logic
- Difficulty
- Hard
- Play time
- 10–20 min
- Price
- Free, in your browser, sign-up optional
How to play
- Move
- Tap a piece, then a highlighted square. Dots show legal moves; rings show captures.
- Special moves
- Castle by moving the king two squares. Pawns promote on the last rank (choose the piece).
- Win
- Checkmate the engine. Stalemate, threefold repetition, the 50-move rule and bare kings are draws.
- Hard level
- The engine searches 3 to 4 moves deep with alpha-beta pruning and positional tables.
How hard is the engine?
The SkillX engine plays Black and thinks for about two seconds a move. It searches several moves ahead with alpha-beta pruning, keeps looking at captures until the position is quiet, and scores positions with piece-square tables, so it develops its pieces, castles and punishes loose ones.
It runs in your browser, in a background worker: the board stays smooth while it thinks, and nothing is sent anywhere.
Strategy and tips
- Control the centre
- Start with e4 or d4 and bring your knights and bishops out before moving the same piece twice.
- Castle early
- Get your king to safety in the first ten moves. The engine is quick to attack an uncastled king.
- Check every capture
- Before each move, look at every check, capture and threat for both sides. The engine never misses a loose piece.
- Trade when ahead
- Once you are up material, exchange pieces. Simple endgames are where a human can outplay a computer's horizon.
- Avoid quick tactics
- The engine sees 3 to 4 moves ahead, so short traps rarely work. Long-term plans (pawn structure, weak squares) do.
Why play Chess?
Chess trains calculation, planning and pattern recognition: imagining a position a few moves ahead and judging which plan is better. Playing a strong engine is a fast way to find your recurring mistakes, because every blunder is punished.
Hard level means the engine beats most casual players. If you are learning, play slowly, and treat each loss as a lesson about the move that lost.
Frequently asked questions
Is this chess game free?
Yes. It is free and runs in your browser, with no download. Signing up is optional.
How strong is the engine?
It searches 3 to 4 moves deep with alpha-beta pruning, checks captures until the position is quiet, and uses positional tables. It is a hard opponent for club-level players.
Can I play Black?
Not yet: you always play White and the engine replies as Black.
Are all chess rules supported?
Yes: castling, en passant, promotion with a choice of piece, check, checkmate, stalemate, threefold repetition, the 50-move rule and insufficient material.
Does the engine send my moves anywhere?
No. It runs entirely in your browser, in a background worker.