Nuanced Chess Rules Reminder
Castling
Conditions: King & chosen rook unmoved; no pieces between; king not in/passing through/ending in check; not in check now.
- Kingside (O-O): White king g1/rook f1; black g8/f8.
- Queenside (O-O-O): White king c1/rook d1; black c8/d8.
- King moves 2 squares toward rook; rook jumps to king's other side.
En Passant
- Pawn advances 2 squares from start (e.g., e2-e4), lands beside enemy pawn on same rank.
- Enemy pawn captures immediately next move: diagonally to passed square, remove advanced pawn.
Only on immediate reply; pawn acts as if moved 1 square.
=Pawn Nuances
- Capture: Only diagonal forward 1 square (move straight only).
- Promotion: Reach last rank → must promote to Q/R/B/N (not king/pawn); underpromotion possible but rare.