For players who find "expert" difficulty too easy in Left 4 Dead, it appears that Valve is upping the challenge for the sequel with "Realism" mode, a game modifier that made an unplanned appearance last night.

The folks at 1UP spotted the Realism modifier nestled away in one of the game's options, then squeezed Valve for details. According to marketing VP Doug Lombardi, Realism is designed for the Left 4 Dead 2 player more skilled, more masochistic than Valve's own testers.

How it's different, exactly, Lombardi wouldn't elaborate. But one might assume that Realism makes the infected in L4D2 act more like their real-world counterparts, requiring headshots to properly dispatch of the game's zombie hordes. That's just a guess, though.

Valve's other Left 4 Dead 2 reveal from last night's event, the "Scavenge" gameplay mode, can be read in more detail. With the game due out November 17th, expect Realism and the rest of the game's well-kept secrets to be revealed soon.


Left 4 Dead 2 Preview [1UP]