I hate all of the license stuff. I believe that you can't copyright mechanics, so there's nothing in the concepts within BKE that you even need a license for.
The CC-BY-SA license gives you the right to cut and paste the text, as I have written it, and use it in your own work. As has been pointed out by others, there's nothing equivalent to the old Product Identity section of the OGL to easily build walls between the stuff you want to retain exclusive rights to, and the stuff that is "community content" in that license.
I'm not a lawyer, and I'm not giving legal advice. It seems like I've seen references to designating certain portions of a work under CC-BY-SA and other portions under other licenses (or retaining full rights), but you need a clear way to designate stuff, and it can get really messy... it's a headache that I don't want to bring onto anyone.
That said, I have a plan to release my own game. This wasn't part of my original plan for BKE, but if I'm putting in this work, I'm going to publish my own thing too (untitled Mini Six project.)
So, here's the plan.
I'm going to continue releasing BKE under the CC-BY-SA license, for now. There's a plan to transition to CC-BY, which gives third-party publishers much more flexibility.
As BKE approaches the "1.0" milestone, I will start putting serious work into my game. (Or to phrase it another way, the current efforts at BKE are the foundation of my game.)
My Untitled product (print/pdf):
- Will use the same rules as BKE.
- All of the mechanics that are included in my game will be released in BKE as well. (It's possible that some statblocks or something really minor like that - stuff that pertains to what I want to keep as my own intellectual property, might be excepted, or "genericized," but any rules will be placed in BKE.)
- As the creator of BKE, I don't need permission to re-use my creation, so this "product" won't have a CC license at all. However, anyone who wants to borrow the mechanics from it will be able to do so via BKE. I hope that makes sense.
- It will have some unique additions, but these will be the "fluff and crust" that brings a document to life. Things like art, advice, commentary, and most importantly mini-settings. These will be the distinguishing features of this product. (Note that I don't intend to release any mini-settings under BKE itself.)
- When I'm ready to release my product, I will re-release the most current version of BKE (the one that is identical to the rules in my product) under CC-BY. (And any older versions too, if that ends up being needed.)
Why wait for CC-BY?
This allows me to retain a "first mover advantage." I get the benefit of being able to publish this version of Mini Six in print before anyone else. (Technically, anyone can do so right now under CC-BY-SA, but they will have to deal with the headache outlined above or they'll have to be cool with the terms of the SA provision, anyway.)
Why did you release things under CC-BY-SA if you plan to do CC-BY later? Why didn't you just wait and do it all at once?
I wanted to get it out there in some form as soon as I could. If something happens to me, at least it has a chance to live on in some form.
What if it takes you a long time to release your product?
I'm bad with deadlines. It probably will take me a long time. So, here's my promise. If I haven't released my thing in a year (by May 9th, 2024), I will release the latest version of BKE under CC-BY at that time.
So you're saying it will be a year then?!
No. I'm saying that I'm giving myself plenty of breathing room. The plan is not to take that long. The year refers to the worst-case scenario. I haven't scraped up the cash for, nor commissioned any art yet, and that's likely to be the factor that has the most influence on my project's timeline. May 9th, 2024 will be the date I'm racing, but when my product launches I will also release BKE under CC-BY at the same time.
I reserve the right to say "to hell with it" and release BKE under CC-BY early at any time.
I intend to keep the community updated on progress.
What I mean is that it won't be surprise release. Some day I'll be able to say that "the text of (my product) is set." This means that version X of BKE is the one that will be identical to the rules in that book. It will remain CC-BY-SA until my book is done (which will entail finalizing the layout, inserting the remaining art as it's finished, and the lead time on DTRPG's print approval process.)
But that will be the head's up to the community: CC-BY is coming and this particular text (and the older ones) will be available soon-ish. If I have a projected date at that time, I'll share it.
So will that be the final version of BKE?
Who can say for sure? I intend for it to be a living document, so any errata should see updates. In addition, if I release more Mini Six material in the future (beyond "the product"), I may fold any new rules in as appropriate. I'm not committing myself to any particular vision right now since it's still early days. There's a future where BKE continues to see updates.