So this is a how I would do 6E thread. An actual 6E not a revision of 5.5. That might be a 5.75 thread.
I woukd use the 5E engine. Perhaps with a stretched bounded accuracy going to +6 to +11. Why reinvent the wheel? Everything else would be up for consideration.
Basically I woukdld survey for certain things. Hard decisions need to be made and some have to be done early. Eg game engine and complexity level.
Question 1. Complexity level.
This is self explanatory. B/X is a 1 or 2, 3.5 and 4E are an 8 or 9. Clearly explain the difference and pros and cons of both.
Question 2. Should D&D be a 10 level game (at launch). Magic would top out at 5th level spells. CR 20 would be the new toughest monsters. Otherwise 20 levels.
3. Archetypes. Should they stay or go? Partly related to 1.
4. Some spell effects would be revised or go away. Simulacrum and wish get revised. True polymorphism, shadechange go away.
5. Hit point and damage totals. Point out that 5.5 characters might deal lots of damage but monsters have bloated HP.
6. Poll for nasty effects using energy drain as an example. I wouldnt bring back old school energy drain but using exhaustion levels instead could be used.
7. Saving throw revision. Poll on if players like the current set up or want better scaling saves. Also point out monsters get them as well. Use pre 3E and 4E as examples. 3E and 5E are the odd ones out here.
8. Potential overhaul of defenses vs magic. Expanded use of greater magic resistance and landing severe debuffs might require debuffing opponents first.
9. Overhall damage dealing spells. Potentially go back to 3.5 suto scaling damage dealing spells. Or upcasting +2d6 vs 1d6 damage. This will overlap with 5. If players vote for less hp spell damage may be reduced as well. Basically look at buffing damage and nerfing save or sucks with 8 and 9.
10. Be clear designers can veto a survey. But mostly if its an impossible or contradictory results.
So basically looking at some big mechanical changes that 5E added. However they may be popular enough you really want to poll about getting rid of them.
Could potentially end up with a simple or complex version of D&D. At first glance it nay look like 5E eg skills but fears, classes, spells, races may all be revised or even cut.
Personally, I think any 6e approach needs to start from
declaring certain things that will be part of it, both in the near-term and in the long-term, even if that might mean some people say "okay then that's not for me", because one of the bigger stumbling blocks of 5e's design has been its need to try to please absolutely everyone all the time, and thus ending up being pretty middling on a bunch of things, or defaulting to what was merely
familiar, regardless of whether it was
good. Familiarity wins surveys, but doesn't win design. I'm specifically thinking of stuff like psionics--and the need to
stake a flag rather than trying to let a fractious and squabbling community determine which of the 7 different paths will be taken.
Once a core ethos has been established, it then needs a clear timetable. TONS of time got wasted during the D&D Next playtest. There need to be limits for how much time gets invested into various things. E.g. the Fighter cannot take a year and a half bouncing around between six ideas before it finally settles on something--if you want to test lots of ideas, awesome, but be ready to WORK HARD to test that much, because design time is VERY VERY finite, and a bunch of the stuff 5.5e had to fix was almost directly because of classes or subclasses getting rushed out the door because they ran out of time. Experimental stuff, really wild out-there ideas, can be saved for a supplemental book later--the focus has to be hard, sharp, continuous, and always moving forward.
Finally,
hire a statistician and a survey designer. If you're going to be using surveys and doing statistics-based game design, have people on staff whose expertise is surveys, and separately, statistics. (Don't try to make one person do both, it won't go well.) I'm not saying either person needs to have some kind of technocratic veto power or whatever. I just think that you need someone on staff whose training and experience is in these two things, because they are essential for getting the task done and NOBODY on the Wizards staff is trained in this stuff. I genuinely went looking, long ago, into the educational history of WotC's employees. Of the ones I could find, three quarters were some variation of Communications, Journalism, Literature, etc.--and all BA, never BS. The closest I got to "math" was that I think one person had a BA in Philosophy, which should've included some classes in things like set theory and logic. Point being, if you're gonna design something that depends on a mathematical, and specifically statistical, structure...it's probably a good idea to at least have ONE person who knows how statistics work.