Basic Trope: A character chooses to resolve conflicts peacefully rather than through fighting, and actually sticks to those beliefs.
Straight: Peaceful Pete does not believe in resorting to violence, and never does, directly or indirectly.
Exaggerated: Peaceful Pete just stands there and takes it as Mooks throw everything they've got at him.
Downplayed: Pete might participate in the fighting, but only against those that are an actual and immediate threat, after nonviolent approaches have failed. He also will not kill them, though he might hurt them. And he doesn't make a habit of fighting in the first place. In other words, he's a Technical Pacifist.
Peaceful Pete is of a religion that forbids violence, even when one's life is at stake.
Peaceful Pete is a priest of the healing goddess and will forfeit her favor if he turns to inflicting harm.
Peaceful Pete sincerely believes that fighting is wrong because his village was destroyed by invading soldiers when he was a small child and he lost his home and family as a result.
Discussed: "Man, Peaceful Pete just took a beating and didn't even fight back. He must be a hardcore pacifist."
Conversed: "Don't you hate when certain shows have a character who is such a devoted pacifist, they won't even lift a finger, even when the villain is beating the everloving crap out of them?"
Peaceful Pete just saw his wife get gang-raped and killed by the Mooks and wanted to save her, but his ideology wouldn't allow it because that would mean fighting them. This takes a heavy toll on him, and he may even start to question whether he did the right thing or not.
Alternatively: Everybody knows that Pete never use violence, even at his enemies, and so his "friends" take full advantage of him, makes fun of him for his cowardly behavior because A Real Man Is a Killer and don't have any real respect for him at all, while his enemies kill him even in their first meeting.
After a breakdown in law-and-order, Peaceful Pete finds himself in a violent setting where his failure to fight repeatedly means that things needed to survive are taken from him, and he realizes he had always counted on the police to act violently on his behalf.
Peaceful Pete registers as a pacifist and so gets to live out his life safely at home while other men are being killed or wounded, and builds a career while they are in the army; when the soldiers come home, he jeers at them as simpleminded.
Horrible things begin to happen in front of Pete, but rather than "sit there", Pete immediately jumps in front of the victim and takes the brunt of the violence. All while refusing to lift a finger against his opponent.
Growing disillusioned with pacifism Pete results to using violence, but seeing that doing so creates Cycles of Revenge and escalates conflicts further Pete concludes that violence, even if it helps him in the short-term, only creates even more problems for everyone in the long-run and ultimately returns to pacifism.
Peaceful Pete gets a What the Hell, Hero? speech by one of the soldiers' kids, saying that they were fighting to protect their homes and their families. The children even accused Pete of being selfish, arrogant hypocrite.