The leader was eyeing him up and down, shrewdly calculating. "Thirsty as all that, are you, my friend?" he asked. Gratefully Bomilcar seized upon the gambit. “Thirsty enough to buy everyone here a drink,” he said.
-- Colleen McCullough, The First Man in Rome
But in other cases the gambit may be a dependent clause introducing or rounding off some larger unit whose illocutionary force it helps to establish.
-- Thierry Fontenelle, Practical Lexicography: A Reader
Gambit is primarily a term used in chess. It came from the Italian idiom gambetto meaning "to trip up."