I'm looking at the Creative Commons licence for the 5e SRD. Here are what seem to be its main features:
* Acceptance of the licence is very similar to the OGL v 1.0/1.0a - rather than referring to "use" of OGC, you take up the licence by "exercising the Licensed Rights under this Public License": section 1.k
* The permissions that are granted seem pretty similar to the OGL v 1.0/1.0a - they include reproducing the licensed work, and permission to "provide [the] material to the public by any means or process that requires permission under the Licensed Rights, such as reproduction, public display, public performance, distribution, dissemination, communication, or importation, and to make material available to the public" including performances, broadcasts and performances. They also include permission to produce Adapted Material, which is material in which the licensed work "is translated, altered, arranged, transformed, or otherwise modified".
* The licence doesn't extend to trademarks: section 2.b.2. Thus, while the licensed SRD contains terms like umber hulk, beholder and mind flayer, WotC has not given up whatever trademark rights it may have in respect of them. But there is no notion analogous to the contractual notion of Product Identity under the OGL v 1.0.1.0a. WotC has requested a particular mode of attribution which precludes compatibility statements of the sort that the OGL v 1.0/1.0a also precludes, and the attribution provision (section 3.a.1.A.i) makes this part of the licence terms.
* The licence isn't viral, as best I can tell. A licensed party who produces adapted material has to ensure that, however they license their work, they ensure recipients are able to meet the requirements of the licence in respect of WotC's work (section 3.a.4). But they are not obliged to license their own work, on the CC terms or any other.
* WotC's offer of the licence is gratuitous, like the OGL, and so WotC can withdraw it, as
the CC FAQ explicitly notes ("As a licensor, you may stop distributing under the CC license at any time"). However, licences once granted last for the duration of the copyright in the work, and furthermore, as the FAQ also notes "anyone who has access to a copy of the material may continue to redistribute it under the CC license terms." This is because of section 2.a.5.A, which provides that "Every recipient of the Licensed Material automatically receives an offer from the Licensor to exercise the Licensed Rights under the terms and conditions of this Public License."
* The licence expressly states that there is no sub-licensing (2.a.1), and so I'm curious about the best legal analysis of the automatic offer - this may differ across jurisdictions, and my thinking is very firmly within the common law framework. One possibility is that WotC has contractually bound itself to make such offers as part of the licence terms; that seems a bit counterintuitive to me, however, as I can't see how there is a sufficient state of mind to actually constitute an offer. Another possibility is that the licensee is conferred a circumscribed agency (and because it would lack any discretion, it may not attract fiduciary obligations) permitting and requiring them to make an offer, to the one who receives the material, with every distribution of the material.
@S'mon, can you help out here? What if anything have I missed or misunderstood?