To help us with this task, we talked with George Fan and Andrew Stein, creators of ; Lauren Jones of , creators of ; and Matthias Höchsmann, PhD, of Gamedoctors, creators of .

Zombies have appeared in games for over 20 years. Titles like LucasArts' Zombies Ate My Neighbors and The Secret of Monkey Island featured memorable zombie antagonists. Of course, these antagonists were more comedic than terrifying. contributor Dan Waingarten cites these games as being kid-friendly. He points out that the hero of Monkey Island is able to defeat pirate ghost zombies with the aid of witty comebacks and a root beer-soaked sword. Meanwhile, the zombies in Zombies Ate My Neighbors can be taken down with squirt guns and popsicles. Terrifying, I know.

But depictions of zombies would evolve into something more genuinely frightening and become a common staple of games. Dr. Matthias Höchsmann of Gamedoctors believes that zombies speak to a unique kind of human fear--not only are they relentless, but their task is to create more of their number. "You cannot negotiate with a zombie. Should you try, you will soon see yourself (and your delicious, delicious brains) eaten. Don't expect any mercy from a zombie, for they have none to give." Games like Doom, Resident Evil, and The House of the Dead utilized this schema; in these games you'll often confront wave after wave of fearless, shambling living dead.

Zombies are not only relentless, but they have a nasty habit of multiplying. The prospect that your best friend can turn on you and become a zombie can become very terrifying, explains Lauren Jones of Ghostbird Software. Of the games we've looked at this past week, Ghostbird's The Raging Dead is the only application that tackles the idea of a zombie outbreak and how quickly such a plague can spread. Entire cities can turn in hours.