When do homebrew suggestions need to be playtested by an answerer?

Question

It is unclear to me when someone needs to provide playtesting for homebrew suggestions and when they don't.

As an example, in this answer, MattDM provides a really good answer for the first half, suggests in-book tools for making adjustment, but then at the end makes a homebrew suggestion that wasn't tested by them.

In fact, they specifically state (emphasis mine)

So, another approach would be to beef up that feature — perhaps make the save DC just "damage taken" rather than "5 + damage taken". But this is a less predictable than the raw HP approach, so I don't suggest it without some playtesting and tweaking.

In this case, they called themselves out that their idea is untested and likely needs work. This alone seems to imply it needs testing and would fall under our bad subjective policy for suggesting untested homebrew and is idea generation.

But I also could easily be too critical of a good answer and I'm trying to understand where we draw the line. By understanding when we require more, it will help in evaluating future answers and build a stronger repository of useful information for stackizens.

Answer 1

As always, it's a continuum.

If someone produces an entire piece of content from whole cloth - e.g. a new character class, feat, spell, monster - we really think they should playtest that before claiming it will do what they think it will. Real game designers know all too well that the thing they write down off top of their head may or may not meet its design intent in real play.

However, on the other end of the continuum is exercise of the existing rules. "I want my monster to be able to heal quickly but without the weird can't die thing that regeneration gives you!" "Well, use the feral template, it gives fast healing." That's a simple application of existing work that pure reason is enough to support. You don't need to playtest that (though if you have, I'll more readily upvote you).

Then there's items in the middle. The question you link to was, in addition to a bunch of strongly supported items, proposing a slight modification of an existing mechanic for that monster. I put a "citation needed" post notice and the poster added citations, so I removed it and called it good and upvoted it.

The more basic and common sense a change is - "add more hit points to increase monster suitability" - the less ad hoc proof of that you need. Once you get into the middle of the continuum, you may get a better balance of upvotes to downvotes if you show experience with something that is more of a stretch. If you are just spewing out a new character class with no testing and claiming it creates a better play experience than an existing one, you are completely talking out of your ear and should be downvoted and citation-noticed and may be deleted as "not an answer".