first move; opening move
Primarily used in board games such as shogi and go for the initial move. Also used metaphorically for the first action in a sequence.
The first move in shogi is very important.
General use for the very beginning of something, often with a nuance of the first step or initial action. Less common than 最初 or 始まり in everyday speech.
His opening move is always bold.
I stumbled right from the start.