1.
strategic opening moves (in go)
In the board game go (囲碁), the opening phase where stones are placed across the board to establish a strategic framework for the rest of the game.
2.
preparatory step; groundwork; strategic move
By extension from the go term, an action taken in advance to prepare for future goals or events. Implies careful, forward-thinking planning.
Usage
The figurative sense (sense 2) is more common in everyday speech. The key collocation is 布石を打つ (to lay groundwork, literally "to place a preparatory stone"), which retains the go metaphor.
Common collocations
Etymology
From the game of 囲碁 (go), where 布石 refers to the opening moves that establish strategic positions across the board. The metaphor of careful advance preparation transferred to general usage.