Concept

Special moves

You might say: castling, en passant and promotion

Castling moves a king and rook together, en passant permits a narrowly timed pawn capture, and promotion replaces a pawn that reaches the farthest rank.

What it does
Adds exceptional legal moves whose exact preconditions and timing matter.
Ask
Did the exact precondition and timing for this special move hold?

What to look for

  1. King and rook moved together
  2. En passant capture after the pawn advance
  3. Pawn on the farthest rank replaced by another piece

Sources

  1. FIDE, Laws of Chess (from 1 January 2023), Article 3.7.3.1–3.7.3.2This capture is only legal on the move following this advance and is called an ‘en passant’ capture.
  2. FIDE, Laws of Chess (from 1 January 2023), Article 3.7.3.3–3.7.3.5When a player, having the move, plays a pawn to the rank furthest from its starting position, he/she must exchange that pawn as part of the same move for a new queen, rook, bishop or knight of the same colour on the intended square of arrival.
  3. FIDE, Laws of Chess (from 1 January 2023), Article 3.8.2This is a move of the king and either rook of the same colour along the player’s first rank, counting as a single move of the king and executed as follows: the king is transferred from its original square two squares towards the rook on its original square, then that rook is transferred to the square the king has just crossed.
  4. FIDE, Laws of Chess (from 1 January 2023), Article 3.8.2.1–3.8.2.2The right to castle has been lost: 1) If the king has already moved, or 2) With a rook that has already moved.

Use it on your project

teardown-apply: hold "Special moves" (special-moves) from the teardown at https://teardownatlas.com/chess/ against my project

Paste it into a coding agent that has the teardown skills.

An AI agent wrote this map with the teardown skill. It can contain errors: check the sources before you rely on a part. About and legal