I am not a lawyer. This is not legal advice.
This may have been hashed out long long ago so sorry if it's a redo. For people in the know, how under the OGL you can create a book with no open content. Anything that you designate PI you can close. OK. wouldn't that just really be fluff? The Slaad is PI I believe.
Not true. You seem to have a fundamental misunderstanding of the way the license works. To wit:
* Wizards of the Coast owns the copyright on the rules, etc. of D&D. They can do anything they want with it because they own it.
* The Open Game License was created by WotC to allow OTHER PEOPLE to do CERTAIN THINGS with a CERTAIN SET of material from the rules, etc. of D&D. This subset of the D&D rules is known as the "System Reference Document" (and, technically, the OGC from Unearthed Arcana).
* Under the Open Game License, there are generally conceded to be THREE forms of content in a work:
1. Open Game Content
2. Product Identity
3. None of the Above
* The function of Product Identity is to provide a shorthand method for "scrubbing out" certain delineated terms from a block of stuff that would otherwise be Open Game Content.
* In other words, you first declare
parts of a work to be Open Game Content. Anything not declared Open Game Content is "None of the Above" (or sometimes, "Closed Content"). Then within that Open Game Content, you declare Product Identity. Thus, Product Identity is "stuff that would be OGC if not for the fact it had been called out as PI." Stuff that was never delineated as OGC is neither OGC nor PI.
After all those bullet points, here's the punch line... the term "Slaad" is not OGC. Nor is it Product Identity. It is "none of the above" - or in other words, normal copyright rules apply.
So you can't have a "Slaadi" but you could have the "green lizard creature from the plane of limbo".
Technically, yes, as "Limbo" is sourced from the public domain.
Why are its stats closed? My question really is HOW can any book have no open content?
Its stats are closed because Wizards of the Coast owns the content. Remember my second bullet point - the OGL is there to allow OTHER PEOPLE to play with certain parts of WotC's stuff. WotC itself does NOT need permission, nor the OGL to work with its stuff.
How can a book have no open content? Simple... the entirety of the intellectual property in the book is owned by the publisher (i.e., is not a derivative of SOMEONE ELSE'S work) or is licensed properly in some other manner. However, deriving something from someone else's OGC requires you (absent another agreement) to declare the derivative as work OGC. Again, though, since WotC owned the system to begin with, they still own all of anything they derive from it (including stuff they designated as OGC), with no obligation to a third party to release it as OGC.
If I derive from their stuff, I have to play by their rules. If they derive from my stuff, they have to play by my rules. Since WotC did not derive their stuff from others, they still get to make the rules.
OK part 2: any derivative works are considered open content.
Remember, the Open Gaming License are the rules OTHER PEOPLE must play by when using WotC's content. WotC themselves do not have to follow the same rules to use their own content.
So wouldn't 4E be held under the OGL?
No. WotC does not have to follow the same rules as everyone else because they OWN the content.
WARNING!!! WARNING!!! POSSIBLY BAD ANALOGY FOLLOWS:
The D&D ruleset is a car. WotC owns the car.
WotC tells you, "you can borrow and use the car, provided you don't repaint it, and don't take it more than 50 miles from home. You also can't replace the engine and transmission with a different one." You borrow the car. You don't replace the engine. You're fine. (This is you using OGC - you play by the rules of the OGL and use only what they've offered).
If you take the car 300 miles away, you can get in trouble. If you repaint the car, you can get in trouble. Why? Because you're not using the car in the way WotC gave you permission for. (This is you using OGC without playing by the rules of the OGL).
Similarly, you can't borrow WotC's truck and take off with it. WotC never gave you permission to use their truck, only their car. (This is you trying to use stuff that isn't OGC.)
By contrast, WotC can take the car 1000 miles away, repaint it, and drop in a new engine and transmission if it wants to. It's WotC's car. Just because they say YOU can't go that far in their car doesn't mean THEY can't go that far if they want to. (This is how WotC can create derivative works and not release said derivatives as OGC).
Heck, WotC can even take the engine out of the car, drop it in their truck, mod their truck with nifty gadgets and chrome, and then tell you, "no, you still can't use the truck - the truck may have the same engine as the car, but the truck is not the car." (The "Core d20 Mechanic" is the engine; but this is how 4E isn't released under the OGL).
Or they can stipulate that you can only drive the truck 5 miles from home and have to bring the gas tank back full every time, no repaints, no engine changes, no modifications at all, you can't even adjust the mirrors or slide the seat up or down - and oh by the way, you must have your cell phone on at all times and if they call, you must bring the truck home immediately. (A more restrictive agreement; this corresponds to the GSL*).
Clear as mud? Basically, WotC owns the system. This means they get to set the rules for everyone else to use the system, and they are NOT obliged to follow those same rules that everyone else has to. Because while we're all "borrowing" it, they "own" it.
* Disclaimer - I'm not saying the GSL is "unreasonable" I'm just trying to show by way of comparison that it is MUCH stricter than the OGL.