Effects that require a creature type...

[Yorae]

My wife asked me a question yesterday that I couldn't answer - what happens if, say, a giant gets polymorphed into a humanoid. Then someone casts enlarge person on them. Then polymorph is dismissed. Do they become a giant that is one size category larger than normal, or does enlarge person fall off because they are no longer a valid target?

[Yorae]

Wow... everyone must be as stumped as I was.

(Sorry for the double post)

[Andreaz]

I don't recall this kind of thing ever being clarified, but typically once you stop qualifying for something you lose access to that something.
So mr polymorphed enlarged giant goes back to being a plain boring giant.

[Coidzor]

On the other hand, there's an argument to be made about whether the spell is one that only checks to see if the target is valid when the spell is first cast and then continues to remain in effect until its duration is expended.

On the third hand, does a change to a creature's form from a spell being dispelled or running out count as a magical effect? Because if so, there's another argument about what counts as a magical size increase.

[supermonkeyjoe]

That wouldn't work in the first place unfortunately, I'm not sure if it's in the books or was errata'd in later but alter self, polymorph and other associated spells and effects don't change the creature's type.

Disregard my idiocy, I've just noticed the line in polymorph that explicitly says the creature type changes.

[W3bDragon]

I'm taking a look at the spell Lesser Vigor for comparison. Lesser Vigor states that it affects a "living subject." Lesser vigor ceases to function correctly when the target becomes anything other than a "living subject." In this case, that means that if the target dies, he no longer qualifies for the spell's criteria and does not benefit.

Taking this approach, it seems clear that once you stop qualifying for any given ongoing spell effect on you, you stop benefiting.

Note that I'm not saying the spell is dispelled, you just stop benefiting from it. In your example, I would say that the giant, once he dismisses polymorph, would be a normal giant and not an enlarged one. However, if the duration of the Enlarge Person spell is still unexpired and the giant recasts polymorph to a humanoid, he would regain the benefit of Enlarge Person.

Obviously, this is all my personal interpretation, I don't have any solid RAW evidence.

[drakir_nosslin]

I once asked the same thing, but then it was about a druid polymorphing into an animal, casting nature's avatar on himself and then dismissing polymorph.

The consensus then was that the spell only checks if the target fulfills the conditions when the spell is cast.

[Medic!]

Sounds like one of those deals that could go either way depending on DM ruling. If I had to make a ruling at the table on this I'd say that the sequence of events is as follows:

Polymorph changes creature from Large Giant to Medium Humanoid

Enlarge person makes Medium Humanoid a Large Humanoid

Polymorph wears off, reverting creature back to its original state, Large Giant.

Since the spell causes the "instant growth" of the humanoid, I wouldn't allow the giant to increase to huge from large when polymorph wore off...it just seems more sensical to remain large to me.