castling: The king moves two squares horizontally
Castling is a move that moves both the king and the castle on the same side. The king moves two spaces horizontally toward the castle, passing the king and stopping next to the king. Both the king's side and backside can be flipped, but each side must meet its own conditions.
- The king and castle involved in the castling have not moved yet; the squares between them are completely empty.
- The king currently cannot be checked, and both the passes and the ones that have finally stopped cannot be attacked.
- Leaving the king or the castle on that side and then returning to its original position will not restore the status of the castling.
When selecting a Chinese king, the game will only display the currently valid castrated target slot. Don't just check if the gap between the castle and the king has been cleared.
en passant: The opportunity is only in the next move
A soldier moves forward two spaces from their starting position for the first time. If the middle square they pass is exactly in front of the opponent's soldier, the enemy can immediately move to that middle space and capture the soldier who just moved two squares. This is called en passant.
The key isImmediately。 If the opponent plays another piece first, they cannot use this opportunity to en passant again. Even if it moves to an empty space, it still counts as a capture; If en passant causes your king to be attacked, that move is also illegal.
Soldier promotion: After reaching the bottom line, choose one of four
When a soldier reaches the farthest row on the board, promotion is required. This site can choose from queen, castle, bishop, or knight. Promotion does not require that this piece has already been captured; there can also be more than one queen on the board.
Generally, the Queen is prioritized because her activity range is the largest; If the Knight promotion can immediately check or execute better tactics, the Knight can also be chosen. First, check the post-promotion situation, then click the selection box.
Remember this quick reference table
| Special move | The most easily overlooked condition |
|---|---|
| castling | The king cannot be being checked or cross the attack square |
| en passant | Can only be used immediately after the opponent's pawn has moved two squares |
| Soldier promotion | When reaching the baseline, you choose from four types of pieces and cannot be promoted as king |