My Ultimate D&D

For quite a while now, I've had a monster in my head -- my ultimate version of Dungeons & Dragons. Built primarily on a d20 chassis (generally Pathfinder 1e, which I consider "D&D 3.75"), it would draw in elements from the D&D 3.5 Unearthed Arcana, Rolemaster, BRP, and D&D 4e and 5e/5.5 to gather up mechanical bits I enjoy from all of those games.

Here's a list of things I'd like to utlize in this project:

* Start with the PF1e chassis. Species, classes, levels, and so on.

* However, use the three "generic" classes from Unearthed Arcana: Warrior, Caster, and Expert. Mix and match freely. No subclasses necessary; no prestige classes.

* Turn D&D / PF class features into a selectable list. Gain features every other level (odd levels), interspersed with feats (even levels). 4e Warlord and 5e/5.5 Warlock features converted and included.

* 0 and 1st level spells ae available as a single feature, available at level 1. Every spell level thereafter is its own feature, requiring the previous level, available at even levels as all other features.

* Switch the d20 for 3d6, a la Unearthed Arcana. Drop ACs by 1 or 2 to account for this.

* Group spells into Spell Lists a la Rolemaster. Use Arcane Domains from UA and Cleric Domains as the core, and group up remaining spells into similar lists. Lists may have "blank" levels as in RM; c'est la jeu. Casters choose Spell Lists instead of individual spells / domains plus spells. Domain special powers are selectable as class features. Divide lists into "arcane", "divine", and "bardic" groups.

* Non-infinite HP growth. Larger starting total than 3.5/PF1e or 5e/5.5 (closer to 4e and RM), possible growth by spending advancement on "body development" as in RM or limited to contrbuting stat growth as in BRP.

* "Magic points" for spellcasting like RM & BRP rather than "slots".

* Spellcasting involves a skill roll a la RM & BRP.

* "Arcane" casting still uses primarily INT, but "sorcerer" style inherent casting moves to WIS. "Divine" casting moves to CHA. "Bardic" casting stays with CHA.

* Possible 5e/5.5 skill list instead of PF1e list, but skill points are still a thing rather than "have/have not".

I could cobble together a basic expansion of this list into a small document, but I would like to do it as a full game, which involves... a lot of work, even with the PF SRD. Grouping spells into Lists, writing out explanatory text and providing examples, putting everything into a full document; argh, what a task. It's definitely a project I'd prefer to tackle with a group. Unfortunately, not many folks are interested in d20 variants these days (4e-based games and 5e-clones are the hotness right now). So, I will continue to dream.

What do you think?