Spells and Magic Item Effects on a valid target that later becomes invalid targets

[Balros]

Hello,

We know of the Shillelagh Precedence, in that the spell checks for validity only upon casting, and the target becoming invalid does not suppress the effect. Does this also work on magic item targeting as well?

Here are two completely different cases.

Case #1) Permanency

Invisibility can be made permanent via Permanency, but only on objects. A dead creature is an object. If that creature is brought back to life, it is no longer an object - would the Permanency effect persist and the creature remain invisible forever (so long as it doesn't attack another creature)?

Case #2) Magic Item Effect

The magic item Fortifying Stone is attached to an object granting it additional hardness and temp HP. Possess Object targets the object, which turns it into an Animated Object and thus a creature and no longer an object. Do the effects of Fortifying Stone carry over onto the creature, giving it temp HP and additional hardness?

[Fero]

This is interesting. What is the Shillelagh precedent?

[Remuko]

This is interesting. What is the Shillelagh precedent?

i think its this


Target: One touched nonmagical oak club or quarterstaff

so after you cast it, its no longer "nonmagical oak club or quarterstaff"

[Balros]

This is interesting. What is the Shillelagh precedent?

Shillelagh targets a nonmagical object either a club or quarterstaff, making it a magic weapon for the duration. A magic weapon is not a nonmagical weapon, ergo, no longer a valid target for the spell. But since targeting is only checked at initial casting, the spell effects persist. Setting a precedent.

[sleepyphoenixx]

All Shillelagh gives precedence for is that a spell effect doesn't suppress itself. Which is just common sense, really.
I'd say the rules on combining magical effects apply here.

One Effect Makes Another Irrelevant

Sometimes, one spell can render a later spell irrelevant. Both spells are still active, but one has rendered the other useless in some fashion.

The wording is a little vague, but if spell B makes a creature no longer a valid target for spell A that rule should apply imo.

For your case 1 that'd mean the Permanency gets suppressed when the corpse becomes a creature again because Invisibility on creatures is not a valid target.
For your case 2 i'm pretty sure constructs count as both creatures and magical items anyway (though i don't recall where the exact rule is from), so there should be no issue.

[rel]

This seems firmly within 'ask your GM' territory.
I'd rule against such shenanigans at my own table, but you do you.

[Fero]

This seems firmly within 'ask your GM' territory.
I'd rule against such shenanigans at my own table, but you do you.

Yeah, this gets into RaI and RaF territory. I am not aware of anything RaW that breaks these combos and I think there are plenty of situations where a spell would continue to work even after the target is no longer viable. That said, the restriction on permanent invisibility seems designed specifically to stop permanently invisible creatures so I wouldn't let it work. Alternatively, I would let it work until the creature took an action that breaks the invisibility.

I am not sure where Fortifying Stone is from so I am not sure of the resolution of that one. However, it sounds like the RaI is that it will not effect creatures.

[Chronos]

Quoth Balros:

A dead creature is an object.
[Citation needed]

As I understand it, when you dive deep into RAW, you find that a dead creature is not anywhere stated to be an object, but is instead a creature with a condition on it (specifically, the Dead condition). Creatures and objects are mutually-exclusive categories (note that a creature can be an item, but it's also nowhere said that "item" and "object" are synonymous).

[Gruftzwerg]

Yeah, this gets into RaI and RaF territory. I am not aware of anything RaW that breaks these combos and I think there are plenty of situations where a spell would continue to work even after the target is no longer viable. That said, the restriction on permanent invisibility seems designed specifically to stop permanently invisible creatures so I wouldn't let it work. Alternatively, I would let it work until the creature took an action that breaks the invisibility.

RAW it works, but not as most people think it works. As you suggested in your last sentence, RAW Invisibility ends as soon as any offensive actions are taken. No matter how much duration remains (even if it was permanent), the spell ends immediately after taking such an action.

It's still sole (permanent) Invisibility and not (permanent) Greater Invisibility!

____

The most known exploit on this matter is Enlarge Person + Polymorph (changes type). When Polymorph changes your type, Enlarge Person doesn't check if you are still a humanoid. The check ain't part of the spells effect and thus is only checked once when the spell is cast.
There are some spells where the effect includes "conditions" to work, but these two (Invisibility and Enlarge Person) don't belong to em.