I don’t want a setting for D&D next.
I flat out said it won’t work, nor will any of the other rulesets I’m familiar with. I stated this several times.
I said D&D Next is probably the closest I could make work out of the systems I’m familiar with because of two very specific features of that ruleset: Bounded accuracy and magic/martial scaling. That’s it. That doesn’t mean I want a setting for it. Because I don’t. Because it won’t work. I’d have to modify so much else I’d serious break it.
It’s really not that complicated.
I’m not creating a simple setting and going “oh well the GM can figure out what works and what doesn’t within whatever ruleset they want.”
As I stated several times: There’s no ruleset I’m familiar with that will allow me to do what I want, and I don’t have the time or inclination to learn another ruleset well enough that I can modify it without seriously breaking it (and relying on the GM to “cover” or “fix” those problems through arbitrary rulings is a cop-out and antithesis to good game design).
What I keep saying is that you don’t need these rules to be *that* defined while the game’s beginning. The GM or Game designer can set them as the need arises.
If the GM has to add rules to make the system work, it’s terrible design.
The rules have to be well enough defined to give you a core to work from.
For example, you want tactical grid movement? Well here’s what you have to think about:
How are you managing speed? Via character ability? How are those abilities created? What is average? Does that average work for all creatures in the setting? How does is change? Is encumbrance going to effect movement? Yes? What is the average encumbrance? What governs that? How does that trait relate to the trait that governs speed? Etc. Etc.
Arbitrarily or ad-hocing these values without grounding them in solid math is how you design a broken system.
You’re correct that you don’t need to figure out all the exact details from the start, but you absolutely have to have a feel for how values relate to each other and how they interact with each other.
You can strap on rules ‘as the need arises’ without consideration to that fact, but that leads to disjointed and disconnected design, and frankly, RPGs stopped being designed that way in the early ’90s (well, good ones, anyway).
Trust me on that.. the first real tabletop game I designed was done that way, and at the end of it I ended up with a 65 page rulebook and a system that was completely impossible to balance because nearly every mechanic in it was completely unrelated in any way to every other. It was seriously a collection of “we’ll add rules and layers as the need arises”. And it was a disaster.