What it means
Interference occurs when a player cuts the defensive contact between two enemy pieces, removing the guard of one or both of them, thus creating potential targets for attack. The player cuts the line between an opponent bishop, rook or queen and a piece or important square they are defending by either placing one of their own pieces at the middle of the defensive line or forcing the opponent to do so with one of their pieces. Interference can be delivered simultaneously with a fork, when the piece in the middle attacks both adversary pieces. The difference between interference and blocking is that interference blocks the defense of one enemy piece over another enemy piece (or important square) and blocking prevents an enemy piece from moving to an escape square by forcing the placement of another enemy piece on the potential escape square. Interference should not be confused with defensive interposition. If a player defends a check or an attack from an enemy piece by interposing a piece in the line of the attacker, this is not interference because that line is obviously not a defensive contact of two enemy pieces.
Why it matters
Mastering tactical motifs helps you convert initiative into concrete gains and avoid common calculation errors.
How to apply it
- 1Check forcing moves first and compare candidate responses.
- 2Identify defenders, overloaded pieces and tactical alignments.
- 3Validate the final position before committing to the sequence.