Definition:
Semiopen games arise from openings where White plays 1.e4 and Black replies with a move other than 1...e5. For example, 1.e4 c5 (Sicilian Defense), 1.e4 e6 (French Defense), and 1.e4 c6 (Caro-Kann) are examples of semiopen games.
Compare Open Games (1.e4 e5) and Closed Games (1.d4 d5).
