Immunization Chess

Immunization Chess

Captures trigger an immune response in nearby pieces. When a piece is captured, all enemy pieces adjacent to the capture square become immune to capture for 2 turns.

Setup

Board: Standard 8×8.

Setup: Standard chess setup.

FEN: rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1

Rules

• When a capture occurs, all enemy (defender’s) pieces on squares adjacent to the capture square become immune for 2 turns.
• Immune pieces cannot be captured but can still be blocked, checked, and moved normally.
• Kings cannot become immune.
• Immunity wears off after 2 full turns.
• Immune pieces still deliver check and control squares normally.
• You cannot capture an immune piece — the move is illegal.
• All other standard chess rules apply.

Win Condition

Checkmate the opponent’s King.

Strategy

Captures create a defensive shield around the victim’s neighbours — making exchanges near clustered pieces dangerous. Isolated pieces are more vulnerable since they have fewer neighbours to immunize. Plan captures carefully: taking a piece that immunizes a more valuable neighbour is often a mistake.

Attribution

Modern variant. Public domain.