>>211556972 (OP)I'm a sucker for this trope, the heroes either lying or just unaware of what's going on, but through acting or random luck they end up succeeding and getting a badass reputation. This is a good movie for it, there are enough lucky breaks and bluffs paying off without it seeming too ridiculous.
Reminds me of "The Man Who Knew Too Little", Bill Murray thinks he's in a fully paid-for role playing experience and that everyone he talks to is an actor, not knowing he's wandered into an actual spy/crime situation. Involving a scene where criminals interrogate him under truth serum to find out who he works for and he keeps answering "Blockbuster video". Completely true, but they assume he's so highly trained that he can resist the serum.
Or King from One-Punch Man, a scary looking but completely normal guy who through complete chance he gets a reputation for being the "strongest hero", to the point where monsters just surrender to him while he stands there having a panic attack.