deus ex slot machina
A literary device used primarily in film in which the protagonists' seemingly impossible dilemma is solved through an unexpected and improbable gambling windfall, such as winning the jackpot.
Moviegoer 1: Couldn't they have thought of a better way for them to pay him back than just winning $80,000 in blackjack?
Moviegoer 2: Yeah, the writers pulled a total deus ex slot machina...
Moviegoer 2: Yeah, the writers pulled a total deus ex slot machina...