Zwischenzug

Zwischenzug is German for "in-between move," from zwischen ("between") and Zug ("move" or "pull"). It describes a disruptive intermediate move — often a forcing check or capture — inserted into a sequence the opponent expects to play automatically, forcing them to deal with a new, more urgent threat first. The earliest documented English-language use of the term appears in Fred Reinfeld and Irving Chernev's 1933 book Chess Strategy and Tactics. The concept also carries an alternative Italian-derived name, "intermezzo" (literally "interlude"), reflecting the multilingual patchwork of borrowed vocabulary that assembled chess's modern tactical lexicon over the 19th and 20th centuries, as German-speaking analysts such as Aron Nimzowitsch and Siegbert Tarrasch contributed increasingly precise strategic and tactical terminology to a game whose procedural vocabulary (en passant, j'adoube) had already been shaped largely by French.