What is Semi-Closed Game?

A Semi-Closed Game is a type of chess opening where White begins play with 1.d4 but Black does not follow with 1...d5. This leads to a variety of openings including the King's Indian Defense, the Grunfeld Defense, and the Nimzo-Indian Defense, amongst others. These games typically allow for a high degree of complexity and strategic depth, with emphasis on control of the center and piece development rather than immediate tactical skirmishes.