FAQ: What is a "shared universe"?
The concept of a "shared universe" may not sound familiar to you, but chances are that you have seen them all of your life. Spider-Man, the X-Men, and most other Marvel comic characters share the same universe, as do most of the characters for each of the other major comic book publishers. Most people who play superhero role-playing games take a shared universe for granted. This week, your game group may be playing out the adventures of the Boston Super-Patriots. Next week it might be the exploits of the Dark Avengers. In each case, if your group is like most game groups, these various superhero teams all coexist in the same setting. This is a "shared universe", and it's a very common occurrence in role-playing, particularly in superhero games.
In the early days of role-playing, sharing a setting with other players, pooling your creative efforts for the benefit of everyone, was limited to those who actually met face to face. With the exception of amateur publications like Alarums & Excursions, most role-players never met each other or had the opportunity to collaborate in a meaningful fashion beyond their own personal game group. The advent of the World Wide Web has greatly expanded those borders. Now it is easy to share ideas and collaborate with players from all over the world. A universe or game setting which was once shared by only a few can now be enjoyed and expanded by dozens, even hundreds of players.
The problem one encounters is that not all of these so-called "shared universes" are, in fact, shared. In a small game group, one rarely worries about copyrights or ownership of the setting. The idea is to have fun, and few people are so paranoid that they think someone will steal their home-grown role-playing setting and try to become rich from it. Once your horizons are expanded to the World Wide Web, copyrights and ownership become a concern. Fortunately, it is very easy to both protect your work from unscrupulous individuals and to ensure that it may be shared and enjoyed by everyone. The means for making this possible is called an "open source" or "open content" license. Several such licenses exist. The most popular licenses, and the ones most appropriate for role-playing games, are the GNU Free Documentation License and the Creative Commons Attribution-ShareAlike license. Of these two, the Creative Commons license is much simpler to use. If you find a "shared universe" on the web, and its contents are made available under one of these licenses, then you can be sure that it truly is a shared universe. You will receive credit for what you contribute, and you may use what others have contributed, as well.
Unfortunately, not everything which is labeled a "shared universe" is one. Some people's idea of sharing means you give to them, and they keep it: all of the "sharing" is strictly one-way. If you find a web site which proclaims itself a "shared universe", but it is emblazoned with fierce pronouncements of copyrights, and which threatens harsh penalties for anyone using the contents without permission, then what you have discovered is not a shared universe at all. For example, you might find a site which has a warning like this one at the bottom of every page:
The Super Wonderful Universe is copyrighted to L. Robert Purblind, and is his solely owned property. Except where otherwise specifically noted, the Super Wonderful Universe, all Super Wonderful Universe characters, and all stories included therein are Copyright 2000-2005 by L. Robert Purblind with all rights reserved under International Copyright Convention. Submitting material (such as but not limited to character submissions, background information, and artwork) for inclusion in the Super Wonderful Universe grants L. Robert Purblind the right to use that material as he wishes, in perpetuity, within the confines of the Super Wonderful Universe. No material on this site may be posted or published elsewhere without the express written permission of L. Robert Purblind.... (ad nauseam)
This is not a shared universe in any meaningful sense of the term.