I can't remember ever having an argument with anyone over the rules of Monopoly, nor even a game that is a bit more complicated, such as Betrayal at House on the Hill. There will always be house rules, but we're discussing specific house rules here that have emerged as a result of unclear rules... I don't see that very often when playing other tabletop games.
Wouldn't you agree that the description of the Disintegrate spell could easily be reworded in a way that gets rid of any confusion?
No. I would agree that you could get rid of
this specific confusion.
So, then... couldn't you do that with the whole book?
No.
Systems of rules become prone to ambiguities or conflicts largely as a matter of scale. Basically, if you have 10 rules, there could be conceivably 45 different interactions of two rules. (There's 90 total pairs, but we ignore order, so it's only 45.) So rule 1 can interact with any of rules 2, 3, 4, 5, 6, 7, 8, 9, 10. Rule 2 can interact with 3, 4, 5, 6, 7, 8, 9, 10 (and the interaction with 1 was already dealt with). If you have 20 rules, it's 190 interactions. If you have 30 rules, it's 435 interactions.
The reason that RPGs tend to have lots more complicated interactions is that their rules are both much more open-ended and much larger than the rules of most tabletop board games. The open-endedness means that the set of possible interactions grows dramatically, because you don't have a small fixed set of options at most points. The huge number of rules means there's that many more special cases that could conceivably be a clash.
If you just didn't
have the disintegrate spell, there's only one possible-conflict I know of with wild shape, which is the question of what happens if the leftover damage is enough to outright kill the initial form, and I think the wording of the wild shape rule tells you that they are thinking about the left-over damage, because they tell you to do something else with it, which implies that it doesn't have the instant-kill possibility, probably.
But say you add another power, like a contingency spell that will fire off a cure wounds spell if you are dropped to zero hit points. Now you have two new questions: One, how does that interact with wild shape, two, how does that interact with disintegrate.
Oh, wait. I missed one. Look at the fiend pack warlock. "when you reduce a hostile creature to 0 hit points, you gain temporary hit points". Does that proc off a "temporary" reduction to zero hit points? If we assume the designer's intent is understood to be that wild shape happens before other things check for zero hit points, then probably not.
What about polymorph effects? Is a druid a "shapechanger"? Say that I am a 17th level wizard with 2 levels of druid, and I cast shapechange. If I assume a new shape, then assume another new shape, and I am reduced to zero hit points, do I end up back in my original form or in the second form I'd changed into?
Long story short: If you think you can write a system of rules this large and this flexible, which is not subject to ambiguities or confusions, you go right ahead and do that, and I know dozens of professional writers who will idolize you forever if you manage it.
