Disclaimer: this is purposefully obtuse.
Other effects in the game which explicitly state they kill you:
Shadows, succubi, massive damage, death saving throws, beholder death ray (notably not even their disintegration ray kills you), power word kill, vampires, mind flayers, night hags, drow inquisitors.
Clearly, if they intended for disintegration to kill you, they’d have said so. Since specific overrides general, and there is no general rule that disintegrated creatures are dead, I rest my case. QED.
A disintegrated creature and everything it is wearing and carrying, except magic items, are reduced to a pile of fine gray dust. The creature can be restored to life only by means of a true resurrection or a wish spell.
Why would you need to be “restored to life” if you weren’t dead?
Because you could later die. So a creature that has been disintegrated, and then later dies, can only be brought back by those means.
If this was the intent of the rules, it would be expressed in explicit, unambiguous language. They don’t write contingency rules for possible future events that haven’t happened this way, and if you interpret rules documents this way, then everything becomes an argument.
The implication of “the creature can only be restored to life by (x)…” is present tense. It applies to the current state of the game following the events described. The language “unattended objects catch fire” in fireball doesn’t mean “unattended objects in the area of a fireball will catch fire if someone sets fire to them.” it means they catch fire.
Language in rules doesn’t ambiguously cater to a potential future state of the game that may not occur. It is describing the current state of the game, like the rules do in all other situations.
To the contrary, if it were intended to kill you it would be explicit. See all the examples I included in the OP.
The “present tense” argument doesn’t hold water when you look at how spells are worded. Let’s take a look at Alarm:
You set an alarm against intrusion…
Present tense. It describes a state change to the game world.
…Until the spell ends,…
Describes an ending to that state. We can conclude that the alarm state lasts until the spell ends.
Disintegration does not describe any such end to the changed state. We can conclude that this rider effect comes into play if the character ever dies in the future.
I’m not misreading anything. “The creature can only…” applies a new state to the creature. After that state has been applied, or somehow reversed (unaware of any way to do this by RAW), then the creature can only be brought back to life by the means mentioned in the spell.
I’m sorry, I don’t know enough about the English language to recognise the difference. What would the phrase be in future tense?
I thought you needed a body part to resurrect? I might be thinking Pathfinder, though cause I mostly play that.
The difficulty of restoring to life someone who is already alive is why such high-level magic is required.
