Harold Stibbins
This oddly named mod points to the next generation of hacking. Created for 2001's hit PC game, Max Payne, it's a sophisticated and literary spin on the work of real-life fantasy author Terry Pratchett.
Counter-Strike
This Half-Life mod-which pits terrorists against counterterrorists-is one of the most downloaded games on the Net. Since September 11, players have been injecting timely touches, including a character image, or "skin," of Osama bin Laden.
The Guinea Pig
An official mod that taught players to mind their virtual messes. Click on Get Cool Stuff, go to Objects, then Guinea Pig.
Star Wars Doom
An example of "total conversion": The game occurs in a conjured version of the film.
Capture the flag
This comprehensive hub features mods based on the old schoolyard contest, made for the series of Quake games.
138 years of Popular Science at your fingertips.
Each issue has been completely reimagined for your iPad. See our amazing new vision for magazines that goes far beyond the printed page
Stay up to date on the latest news of the future of science and technology from your iPhone or Android phone with full articles, images and offline viewing
Featuring every article from the magazine and website, plus links from around the Web. Also see our PopSci DIY feed
Science is reinventing play, from extreme sports to gamification to ridiculous roller coasters to the playgrounds of tomorrow, and this issue is chock full of fun. Also, on a less fun note: Did global warming destroy my hometown?