Medicine Man: Don't worry, it could be worse - he could be a white guy.
Roy O'Bannon: Holy crap, the vultures are eating my head.
Roy O'Bannon: There's more to life than money. I hope you learn that one day.
Roy O'Bannon: Come on. We're men, we're not pinatas.
Sioux Chief: Daughter, husbands like Man-Who-Fights-in-Dress don't come along every day.
Chon Wang: We stick together. We are partners.
Roy O'Bannon: That's beautiful.
Chon Wang: You killed my uncle.
Roy O'Bannon: Bull! That was Wallace! All the way.
Chon Wang: He was one of your bandits.
Roy O'Bannon: He wasn't part of my gang! He was a new guy! And he's crazy as a road lizard.
Roy O'Bannon: So who are you?
Chon Wang: I'm an Imperial Guard to the Emperor of China.
Roy O'Bannon: China... what's with the book?
Chon Wang: The book belongs to Princess Pei Pei. She was kidnapped from the Forbidden City.
Roy O'Bannon: I like that, Forbidden City, a princess, kidnapped! It's so mysterious.
Princess Pei Pei: Father, is this my husband-to-be? He's a toad. If the Emperor is so fond of him, why doesn't he marry him?
Chon Wang: I got an idea: why don't I pretend I'm sick, and then you can attack the guard when they come in?
Roy O'Bannon: Oh, you mean the sick prisoner routine? Does that still work in China? 'Cause here it's sorta been done to death.
Roy O'Bannon: I don't know karate, but I know kar-azy, and I will use it.
Roy O'Bannon: Yes, John, I've heard all about the Emperor. Must be one hell of a man.
Chon Wang: He's only twelve.
Roy O'Bannon: Are you kidding me? You're sitting here, waiting to die for someone whose balls haven't even dropped?
Chon Wang: See! I told you so.
Roy O'Bannon: No, you said "wet shirt don't break," not "piss shirt bend bar".
Marshal Nathan Van Cleef: Mighty impressive hardware you packin' there.
Roy O'Bannon: Why don't you get your eyes of my package, you twisted son of a bitch.
Chon Wang: He took the gold.
Roy O'Bannon: Is that all you care about, the gold? Shame on you.
Lo Fong: One thing about the Chinese, Mr. Andrews. We do not renegotiate.
Imperial Guard: On the battlefield, a soldier can't always obey the General's orders.
Princess Pei Pei: Whatever you think I'm going to do for you, you're wrong.
Roy O'Bannon: Is that her? She's pretty! Grab her.
Chon Wang: This is the West, not the East. The sun may rise where we come from... but here is where it sets.
Answer: During the Qing Dynasty it was compulsory for men to wear a queue to prove loyalty to the Manchu rule. Refusal to follow can result to execution considering that as treason. Also, he not only prevented him from going back to China but also preventing him from informing the Emperor of his crimes without his queue.
Yes, but in fact, Jackie Chan wasn't wearing a queue in the movie. He only had the pony tail. His head should have been shaved half bald, especially if he was the Emperor's Guard. They just didn't want to show Jackie Chan in a half-bald hairstyle.
Similarly happened in 1976 film Hand of Death in which Jackie co-starred in. That film too was set in the Qing Dynasty but all men still had their queues but no shaved temples. The slaves in Shanghai Noon however some of them did actually have that hairstyle correctly having both queue and front temples shaved bald.