While neither of us knows, the original hope was that wotc doesn't just toss the entire conversation & decision making process of adapting spells to fit ravenloft entirely onto GMs & leave players without something they could point at as if such a thing was something unforeseeably far out of left field to be worth including any pagespace for.
They honestly
don't need to give much detail about how spells work differently in Ravenloft.
First--and I'm going through the Black Box here--like many things in AD&D, they used somewhat flowery language that isn't really necessary. For instance:
When they could have simply said "Dispel Evil: This spell doesn't work on creatures" and saved most of a paragraph. Does the spell work on enchantments, a player may ask. Well, is the enchantment a creature? No? Then yes, the spell will work on enchantments.
There are basically four rules for altering spells that I can see them using in 5e:
1. You can't use a spell, magic item, or trait to teleport outside of Ravenloft or travel to another plane.
2. If you use a spell, magic item, or trait to summon a creature to you from another plane of existence, that creature can't return to its home plane when the spell's duration ends, and you no longer have any control over it. Possibly this rule can be altered by talking about how the Mists corrupt summoned creatures--a mini-template would be nice, but WotC has been reticent about using those.
3. Spells that target corpses, inflict necrotic damage, or reduce the target's hit point maximum or attribute score require a Dark Powers check. But since they're almost certainly not including Dark Power's checks in this edition, this rule can be ignored.
4. Spells can't be used to teleport or scry past the borders of a Domain, but work normally within a Domain.
Maybe they need to change the detect/dispel/protection from evil and good spells, but beyond that, they probably don't have much to change on an individual basis.
Everything else for altering spells to fit Ravenloft is going to be about flavor.
I
seriously doubt they're going to give necromantic spells the huge boost that they had in 2e RL or say only evil characters can cast certain spells.
You mostly scorned the very idea because someone could do it.
No, no I didn't. Not in the slightest.
TCoE devotes about 3/4 of a page to personalizing spells without actually changing anything mechanically & probably half if not more of that about chicken legs on spells rather than anything mechanical.
That's a piece of quote and a piece of art.
The purpose of that section isn't to change a spell on the mechanical level. It's not about applying metamagic or researching a spell. It's to aid
players in roleplaying their characters more by imagining how their personalities affect their spellcasting.
