The case law is said to have distinguished between forumlaic tables, collected public data, and non-formulaic tables. Collected pubic data (phonebooks) and formulaic tables (such as log tables and root tables for math) can't be copyrighted, but add a couple fictional ones in, and it can. Same for Maps; totally accurate, no copyright, but add a fake town or two, and misspell a couple names on purpose... I've heard this from two then-practicing IP lawyers in the 90's, and seen references to it online, but not looked up the cases themselves.Depends. Tables and such are not protected. Superfluous descriptions like examples are. The stated rules are not. This is all in the USA of course. I just worked with a company that just finished that for a D&D like game that had been using the SRD and has now tossed the SRD. Wasn't really needed in the first place as the SRD contained almost zero I.P. to start with
The IP of the SRDs is the exact wording of the rules. Now, in the case of D&D, the exact wording is pretty sloppy, so rewriting, while not trivial, is doable. The ability to simply use the bulk of the text as is has strong commercial value, in that the other uses establish a common understanding of that exact wording; paraphrasing can often cause misinterpretations.
Likewise, some SRDs go even further; Free League (aka Fria Ligan) released a single SRD with various options from across the line... you get one SRD, but it's got options from at least 5 different flavors of Year Zero (MYZ, Vaesen, Alien, Forbidden Lands, Tales from the Loop), and is a menu of choices to use to build your customized flavor, and leaving room for you to modify bits, but to use that well defined text where you don't need to customize. I don't know if there's a Swedish version, but if their is, using the SRD also means easier translation.
That "exact wording" is a thing of value.
Plus, for France and Germany, where paraphrases still infringe, the SRD is even more useful.