also: セオリ
Used for a systematic explanation or set of principles, similar to English 'theory'. Often appears in academic or analytical contexts.
彼のセオリーはまだ証明されていない。
His theory has not been proven yet.
standard procedure; common strategy; established tactics
Refers to a widely accepted method or approach in a particular field, such as business, games, or sports. Implies a conventional or textbook way of doing things.
このゲームでは、まず中央を取るのがセオリーだ。
In this game, the standard strategy is to take the center first.
The manager made substitutions according to the standard strategy.
The player surprised the crowd with a move that defied conventional strategy.
Beginners should practice by following the standard approach first.