Being the computer professional that I am, I'm very sensitive to licensing, both in software as well as in other media. I'm very much aware of what rules folks believe I can use their product under, and if I don't like the license terms, or feel them unfair, I'll try to not use the product.
One of the creative enterprises that has licensing is the world of Role Playing Games (RPGs). Since there's such an overlap between those who play with computers and those who play with RPGs, it's only natural that licenses made the jump. There are several licenses, fan policies, and the like governing the use of these games, and I've found a correlation between how the company treats their fans and how the company licenses their product. On certain occasions it's even influenced whether or not I'll even check out a particular game system (as noted in my discussion of Wizards of the Coast / Hasbro and their move from the permissive Open Gaming License vs the newer, more restrictive Game System License) . Because of that move, I'll likely never touch a D&D 4E product ever again.
It's no secret that I am a complete fan of Posthuman Studios licensing of Eclipse Phase under the Creative Commons license. The license is very permissive, allowing anyone to remix, redistribute, and reuse their product as long as it's attributed, and not for commercial gain. I have several ideas percolating in my head for using the stuff from Eclipse Phase in a computer game, mostly because they implicitly give me permission. I'm also a fan of Steve Jackson Games GURPS system, which is completely locked down by copyright. Why is that? Because they have a very liberal fan policy, which states that while I can't re-print their mechanics verbatim, I can use them for my own creations, as long as they aren't commercial. They make it very clear what they like, what's a grey area, and what will piss them off, and I find them very reasonable.
There are also several games that I appreciate the licensing terms. FUDGE releases all of their mechanics under the Open Gaming License as Open Gaming Content, and permits them to be used both commercially and non-commercially. This in turn has permitted Evil Hat Productions to create the derivative system FATE, which in turn releases it's mechanics under the same terms. This in turn spawned off several variants of FATE, including Diaspora, Strands of Fate, ICONS, and Starblazer Adventures / Legends of Anglerre, all of which are still very capable of spawning other games. Most of the content of these games is released as Open Gaming Content, with the exception of some of the licensed bits of Legends of Anglerre and Starblazer Adventures. Should I decide to make a RPG game, I could easily take one of these as a framework, and get to work. Because they're great systems, I'd be a fool not to at least consider it. These companies also are very open with their customers, and I feel like a valued participant in their creative process rather than just a funnel with a wallet attached.
So we've seen examples of the more permissive licenses. But not every company feels the need to give back. One game system is Castles and Crusades. Castles and Crusades is essentially a remixed version of the D&D 3.5 rules, with a mechanic where if you're doing something that you know (prime attribute), you roll to try to best a number of 12. If you are trying something that isn't against a prime attribute, you roll against an 18. Troll Lord Games calls this system the SIEGE engine, and they use it in several of their games besides Castles and Crusades. It's a mildly innovative take on the d20 engine, and simplifies the overall d20 system from which it derives. Since the d20 mechanics are Open Gaming Content, you'd think that the SIEGE engine would also be Open Gaming Content, out of respect for the roots from whence it came. Unfortunately I realized with the release of the Castle Keeper's Guide that there was little in there that could be considered Open Gaming Content. After re-reading the Player's Handbook, I realized that they carefully re-released the pieces that were originally Open Gaming Content back as OGC, but ensured that the parts that were part of their SIEGE engine were kept as their own. It really struck me as disingenuous of them to build upon open foundations, yet close off their own little spin. Sure, they're well within their rights, but it rubbed me the wrong way, enough so that I'm no longer purchasing their books, and selling off the ones that I have. They may be the nicest guys in the world but their license was a turn-off.
What's great about companies that open up their products is they give permission to the fans to tinker with their systems. I'm sure just about any budding game designer has spent their time playing with mechanics, seeing what works well, and what breaks the system horribly. Much like I did with my early BASIC program listings, tweaking is a part of learning. Open licenses give designers, fans, and developers the freedom to play with these systems and create something new. What's even better is giving those who want to develop off of your work the freedom to create, much the same way that you did. When game and software companies lock down their game rules with licenses or other restrictions, they're tacitly saying that they don't want to afford you the opportunities that they had. It's selfish. Granted, some people just want to play the game, but for those of us who like to tinker, and enjoy the freedom of tinkering, it's liberating to know that you have the blessing of those whom you're game derives.
Because games and game rules are better when they're shared.