From publisher blurb:
The mission of U4
is to present 4th EDITION D&D
rules for use in non-fantasy settings. These include pre-modern settings, contemporary settings, and those that are far flung fantastic and futuristic. U4
is perfectly suited for any of these following campaigns:
- Modern warfare
- Space opera
- Urban fantasy
- Wild west, with or without aliens
U4 has no included setting, allowing you to explore the rules in whatever context you wish. The rules are offered in a general way, not assuming any time period. The equipment lists a wide range of various firearms. Though most are modern, there are quite a few that are retro and futuristic.
- The new "Ladder" system which offers more adjustability with character creation. Modify your class with one of seven ladders.
- Eleven new classes including sniper, faceman, infiltrator, and the grappler.
- New armor including powered combat suits.
- New skills & feats.
- All new weapons including traditional firearms, rocket launchers, and laser rifles.
- Pimp your auto. Purchase vehicles and modify their features.
- All new opponents from fanatics to tanks.
The difference in version page count appears to be one of font size and formatting; the OGL version uses a MUCH larger font, but all the info appears to be the same.