From a post on Kotaku:
The game opens on the game’s four characters at ground zero two weeks after the rise of the zombies. Left 4 Dead will have a short introduction, created by the team behind the Team Fortress 2 cut-scenes, but that will be the only cut scene gamers will see in Left 4 Dead.
Instead the story will be told through the game’s more than 8,000 lines of dialog and the occasional messages scrawled on the walls of the game’s maps, said Valve’s Chet Faliszek.
And the games plentiful dialog, Half-Life 2 only had 2,500 lines, isn’t meant to be experienced the first time through, or even the fiftieth. The dialog is selected by the specific situation, so it could be weeks or months before a gamer stumbles upon a particular line which might shed a bit more light on the character’s back stories.
So this is an interesting development for conveying the story line. While the individual gamer or group of gamers is going to want to play through as much as possible to get the story line, I think Valve is going to find alot of online collaboration over what the story line is. It won’t change anything in the game, but should provide for some late night heated discussion on the interweb.
