"21" is the fact-based story about six MIT students who were trained to become experts in card counting and subsequently took Vegas casinos for millions in winnings.

Ben Campbell: Winner, winner, chicken dinner!
Cole Williams: Always account for variable change.
Ben Campbell: I had a 1590 on my SAT, I got a 44 on my MCAT, and I have a 4.0 GPA from MIT. I thought I had my life mapped out, but then I remembered what my non linear equations professor once told me, always account for variable change... I let down my good friends, but as it turns out, they weren't too bad at simple math either. I scored the prettiest girl in school. I got beaten down by an old school Vegas thug who was having trouble accepting his retirement, but I worked out a deal with him that got him a nice pension... And I lied to my mother, but I confessed a lie and well, she still loved me... So my senior year of college I joined this team and I learned this new skill. I went to Vegas 17 times to use it. I made hundreds of thousands of dollars counting cards. And then I had it all stolen from me, twice... How's that for life experience professor? Did I dazzle you? Did I jump off the page?
Ben Campbell: [in regards to Mickey Rosa inviting him to the Blackjack team] So why are you telling me?
Micky Rosa: Well, let's just say a spot opened up on our roster.
Ben Campbell: How?
Micky Rosa: Jimmy got a job at Google.
Ben Campbell: Jim... Jimmy got a job at Google?
Micky Rosa: Yeah, it's catchy, I know.
Ben Campbell: Well, if you're making so much money at this then why did he take it?
Micky Rosa: Ben, I said Google, not Sizzler.
Micky Rosa: [while Choi is stealing everything that isn't nailed down in the hotel room] *Hey!* You steal The Bible, you go to Hell. Those are the rules.
Choi: Like I'm not going anyway.
Jill Taylor: You know what I like most about Las Vegas? You can be whoever you want to be.
Kianna: Dude, I lost track 20 cards ago.
Micky Rosa: Don't call me dude.
Micky Rosa: The only thing worse than a loser is someone who won't admit he played badly.
Micky Rosa: He says, "Ben, do you want to stay with door number one or go with door number two?". Now, is it in your interest to switch your choice?
Ben Campbell: Yeah.
Micky Rosa: Well wait, the host knows where the car is. So how do you know he's not trying to play a trick on you - trying to use reverse psychology to get you to pick a goat?
Ben Campbell: Well I wouldn't really care. I mean, my answer's based on statistics - based on variable change.
Micky Rosa: Variable change? But he just asked you a simple question.
Ben Campbell: Yeah, which changed everything.
Micky Rosa: Enlighten us.
Ben Campbell: Well, when I was originally asked to pick a door, I had a 33.3% chance of choosing right. But after he opens one of the doors and re-offers me the choice, it's now 66.7% if I choose to switch... So yeah, I'll take door number two and thank you for the extra 33.3%.
Micky Rosa: Exactly. People, remember - if you don't know which door to open, always account for variable change.
Micky Rosa: Now see, most people wouldn't take the switch, out paranoia, fear, emotions. But Mr. Campbell, he kept his emotions aside and let simple math
[in a game show host voice]
Micky Rosa: get his ass into a brand new car!... Which is better than that goat you've been driving around campus...
Philosophical Gambler: Yesterday's history, tomorrow's a mystery.
Philosophical Gambler: It's all what you do in the moment, baby.
Cole Williams: If I see you in here again, I will break your cheekbone with a small hammer. And then I will kill you.
Micky Rosa: [on why he needs Ben to be the second high roller] Because I don't trust the girls and Choi is... well, Choi.
Ben Campbell: I'm not the same guy I was back in Boston.
Miles Connoly: I've got some good news, though. I just saved a bunch of money on my car insurance.
Micky Rosa: You are only ever as good to me as the money you make!
Choi: [laughing and taking a video while Ben is goofing off as a new persona in the mirror] No please, keep going, this video's priceless!
Micky Rosa: Choi, you made five grand last night. So would you stop stealing 9 cent pens and everything you can get your hands on from the maid's cart. It's embarrassing!
[beating Ben Campbell up and looking at his real ID]
Cole Williams: *Oh*... you go to MIT. So you understand all this. You're a smart boy, eh?
Terry: [cackles mean and tough with Cole] Smart boy.
Cole Williams: Tell me something... does Professor Rosa still teach there?
Ben Campbell: [closes his eyes as Cole Williams throws a savage punch to his face]
Jill Taylor: [after opening the curtains in Ben's room] Nice undies!
Choi: Basic strategy says that you should hit that!
Jill Taylor: [in Foxx Strip Club] So do you want a private dance?
Ben Campbell: How much?
Jill Taylor: 20 a song, 30 song minimum.
Ben Campbell: I don't know. Sounds expensive.
[they kiss]
[a man is being beaten brutally by Cole Williams and his partner, Terry]
Cole Williams: You think you can beat the system? This *is* the system... beatin' you back!
[Cole smacks the counter in the face]
Cole Williams: You wanna count cards, you do it in Atlantic City! Get him up.
Terry: [growling] Let's go. Get up! On your feet!
Cole Williams: Count to five. Count to five!
Card Counter: [disillusioned] What?
Cole Williams: Count to five so that you don't have brain damage, you can go home.
Terry: Start with One.
Card Counter: 1, 2, 3, 4, 5.
Cole Williams: Good. Now... stop counting!
Micky Rosa: This isn't about me... you little infant!
Ben Campbell: Man, that sugar's sweet.
Ben Campbell: [after Jill wakes him up when their plane arrives in Boston] I seem to be waking up to you a lot.
Jill Taylor: Don't get used to it.
Micky Rosa: [Referring to Ben] I think he's gonna be ready for our little trial run tomorrow.
Micky Rosa: What's the count?
Choi: Uh, plus nine?
Micky Rosa: You're just saying that because Jill did.
Micky Rosa: [to Ben about card counting] What were going to do is perfectly legal and they can't do a single thing about it.
[very next scene: in a concrete room, bare bulb lights, a fist hits a guy who's strapped to a chair: he's bleeding/sweating]
Cole Williams: You think you can beat the system?
[shows guy his meaty fist]
Cole Williams: This *is the system*... *beating you back*
Micky Rosa: [Micky is talking through the "Game Show Problem"] People remember. If you don't know which door to open, always account for variable change. Now most people wouldn't take the switch, out of paranoia, fear, emotions. But Mr. Campbell kept emotions aside, and let simple math get his ass into a brand new car!
[class chuckles]
Micky Rosa: Which is better than that goat you've been driving around campus.