Openings
What is a irregular opening in chess?
- Opening
- Plans
- Move Order
Irregular opening is an opening term: early 19th-century chess literature classified all openings that did not begin with either 1.e4 e5 or 1.d4 d5 as "irregular". As opening theory developed and many openings previously considered "irregular" became standard (e.g. the Sicilian Defense), the term gradually became less common. Opening books today are more likely to describe debuts such as 1. Learn the plan, pawn structure, and typical piece placement behind the term, not just the name.
What to look for on the board
- Development, center control, and king safety.
- The pawn break each side wants.
- Whether a move creates a familiar structure.
Related terms
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