During the filming of the famous TV sitcom, 'The Big Bang Theory', the cast rarely deviated from scripts, but an impromptu moment by Kevin Sussman, playing the character Stuart, helped evolve his minor part into a larger role. Despite the predominantly script-bound nature of such shows due to tight schedules, there are always exceptions. Sussman’s improvisational skills shone during a Season 3 episode "The Guitarist Amplification," where his character confessed his enduring love for Penny, played by Kaley Cuoco, a detail not scripted, leading to the evolution of his role. When Sussman joined the show in Season 2, his character had a limited course involving some minor encounters with Penny. Had it not been for Sussman's impromptu expression of love towards Penny onscreen, his character might have faded into the background. This corroborates that instincts can secure larger roles, even if it's not a universally relative theory. While series writers often correct non-landing jokes during filming, they are open to joke substitutions by actors as Sussman did.