It's not even that. Derivative works are a different can of fish, and licensed as such. Certain things cannot be copyrighted. The courts have already ruled on that. So if I create a system that uses a d20 and 6 stats and hit points, that is not a derivative work. That is inspired. A derivative work would be taking the SRD and deriving a product from that. Totally different animal.
This exerpt was taken from wikipedia
Originality requirement
For copyright protection to attach to a later, allegedly derivative work, it must display some originality of its own. It cannot be a rote, uncreative variation on the earlier, underlying work. The latter work must contain sufficient new expression, over and above that embodied in the earlier work for the latter work to satisfy copyright law's requirement of originality.[<em><a href="Wikipedia:Citation needed - Wikipedia" title="Wikipedia:Citation needed"><span title="This claim needs references to reliable sources. (February 2025)">citation needed</span></a></em>]Although serious emphasis on originality, at least so designated, began with the Supreme Court's 1991 decision in Feist v. Rural, some pre-Feist lower court decisions addressed this requirement in relation to derivative works. In Durham Industries, Inc. v. Tomy Corp.<a href="Derivative work - Wikipedia"><span>[</span>13<span>]</span></a> and earlier in L. Batlin & Son, Inc. v. Snyder.<a href="Derivative work - Wikipedia"><span>[</span>14<span>]</span></a> the Second Circuit held that a derivative work must be original relative to the underlying work on which it is based. Otherwise, it cannot enjoy copyright protection and copying it will not infringe any copyright of the derivative work itself (although copying it may infringe the copyright, if any, of the underlying work on which the derivative work was based).
By your description of how information/mechanics are taken it sounds as though you are creating works of your own by taking the work of others, and adapting them to your own system, which only the copyright holder is allowed to do, except if you have permission. While I agree mechanics are not inthemselves protected, the act of how you are acquiring them may still be enough to get you in trouble and call into question your work.
While I can understand that some may take my position to exclude all other systems in order to remain original as a negative, I feel that by not copying others, while mindful of what has worked or failed, I can move ahead of people who wish to do this only as a hobby.
Instead of drawing from the pool of, what everone else is doing, I want my product to stand out, and not be doing what everyone else is doing. The danger of taking from everyone elses ideas is that things become generic over time, and Joes RPG is just Siamon's RPG with different dice.
Now is the best time to mix with people on the site because I can look at what has failed, and what peoples main considerations are. I will say this tho, for every mechanic out there, there will almost always be someone who likes it and some one who will complain about it. It is impossible to please everyone, so I will not attempt to try and do so.