opening gambit

One's initial or opening stratagem, maneuver, or tactic meant to give one an advantage. It was a risky opening gambit for the team to throw a Hail Mary on the first play of the game, but it took their opponents by surprise and resulted in a touchdown. The candidate's opening gambit in the debate was to bring up his opponent's marital infidelities, which had come to light in recent weeks.

Fig. an opening movement, tactic, or statement which is made to secure a position that is to one's advantage. The rebel army's opening gambit was to bomb the city's business district. The prosecution's opening gambit was to call a witness who linked the defendant to the scene of the crime.

The first move in a contest, game, or competition of some kind. The term comes from chess and is actually redundant, since in that game gambit signifies a way of opening the game that involves sacrificing a pawn or other piece in order to gain some advantage over one’s opponent. It was being used figuratively by the mid-1800s, and for some reason opening was added in later decades.