Refers to a deliberate plan or strategy, often in a formal or systematic context. Slightly literary or formal in tone.
We need to devise a new plan.
He deceived the enemy with a clever stratagem.
Composed of 方 (method, direction) and 略 (abbreviation, strategy). The combination conveys the idea of a method or plan. The exact historical derivation is uncertain, but the kanji components are conventionally associated with this meaning.