You know where it's from, though? Sicily. Not a thing to do with vampires. In the Mafia, a guy with a "bloody mouth" is a guy who needs to be watched -- because he enjoys killing. You've seen the movies -- you know that in the balancing act of organized crime, adding an element like that, someone who'd kill for fun if he couldn't do it for money -- that always spells disaster. And disaster is the stuff of which nightmares are made.
Great phrase, huh? Bloody mouth. It's so feral. Imagine just how much damage you'd have to DO to have a mouth covered in blood. Imagine what the other person would look like. Now that's horror.
Interesting, too, that it's such a vampiristic image. I mean, think about the way Vampire: the Masquerade is often played -- think of the way the Camarilla was portrayed in Kindred: the Embraced. It's the Mafia with teeth -- literally. All the stuff about clan politics, the mechanics of the Masquerade, conclaves ... all of that can be mapped onto organized crime.
So. I think it's pretty clear that that kind of dynamic accounts for a large portion of Vampire's success. Why aren't there any gangster games? TSR had Gangbusters a ways back, when I first got into gaming, but judging from the name (I never played it), it was more of a G-Men thing. Nothing wrong with that -- there's fun to be had on both sides of the tracks. But where's the Castellamarese sourcebook? The official Sopranos tie-in game from West End? Or GURPS Mobsters?
I suppose a gangster game could use any system which will work for a modern setting (ie, GURPS, Call of Cthulhu, most superhero games, White Wolf's Storyteller system, and so on). After all, it's not like we're talking about Gangster: The Racketeering, here. There are no Disciplines, or superpowers, or magical spells. But a game should involve a certain amount of flavor, which I think is GURPS's only weak point; the main book just isn't very interesting to read, so you really have to sell the worldbooks and use them to hook folks into the main product.
Anyway, that's a tangent. The point is, although there aren't many special rules you'd need for a gangster game (maybe some guidelines for shootouts, especially those nice tasty three-way standoffs like the climax of True Romance), there is a lot of important information that the average GM is going to want to have on hand. And some help capturing the flavor of "Mafia stories" would be good.
