Interference (chess) Interference (chess) In the game of chess, interference occurs when the line between an attacked piece and its defender is interrupted by sacrificially interposing a piece. It is a chess tactic which seldom arises, and is therefore often overlooked. Opportunities for interference are rare because the defended object must be more valuable than the sacrificed piece, and the interposition must itself represent a threat. In the position at left, White to play will apparently be obliged to retreat the knight from f5, because the squares to which it could advance are all guarded. However, the interference move 1.Nd6+ interrupts the
History of chess by the common public, and even the courtly society, which continued to enjoy the now-prohibited chess tournaments uninterrupted. The pieces, which had been nonrepresentational in Islamic countries (see piece values in shantranj), changed shape in Christian cultures. Carved images of men and animals reappeared. The shape of the rook, originally a rectangular block with a V-shaped cut in the top, changed; the two top parts separated by the split tended to get long and hang over, and in some old pictures look like horses' heads. The split top of the piece now called the bishop was interpreted as a bishop's