Can you heighten a spell, but choose lesser effects?
For example, could I cast invisibility as a 5th-level spell, but choose to take the 2nd-level effects (specifically the longer duration, ends on hostile action)?
Let's say that I'm a bard sneaking into a fortification known to have hazards that counteract magic, chiefly illusions like invisibility. In such a case, I would want a longer duration since I will likely need to explore for some time and (short of getting caught) I'm unlikely to see any combat anyways, but also would need the higher spell level to avoid getting the spell counteracted.
Please explain why or why not.
Because there are no rules explaining how this would work for Counteract effects. If you spent a 5th level slot to cast Invisibility with the 2nd level effects, what would the counteract level be?
Also Enlarge explicitly allows you to pick a lesser effect, meaning the default is that you can't do that.
This is a question that we have gone back and forth on before.
The rules don't really say one way or the other.
Some spells have problems because they are automatically heightened - such as Wild Shape.
Other spells have specific overrides that allow them to be cast with a lesser effect. But overrides of what? I am not sure.
So I can't really tell whether it is intended to generally allow casting an underpowered version of a spell or not. But RAW doesn't really support it.
I say it depends on the situation.
For example, I can't think of a good reason for an expert spellcaster not to be able to lessen the effects of the light cantrip, if required.
Ad the same can be said about other spells.
Invisibility for a spontaneous spellcaster may be different, because of signature spell works.
If the bard chose invisibility as lvl 4 spell ( no signature) they just made a choice.
Alternatives may be:
- taking either the lvl 2 and lvl 4 version.
- making invisibility a signature spell.
- using scrolls and other consumables.
I think the Balor gives us an example that while it might be an anomaly, seems to show us that one can use a lesser effect. Balors have unlimited Dim. Door at 5th level, which comes w/ Immunity for 1 hour (which the 4th level version does not). Balors also have Dimensional Dervish which lets them cast that Dim. Door as a single action. If they were stuck casting DD w/ only access to the 5th level effect, then they wouldn't be any kind of dervish; they'd cast it once and be done for an hour. Meanwhile most demons cast DD at 4th at will and bop about? That'd be kind of funny since lesser demons could typically escape their cruel bosses, yet off obviously.
So yeah, it seems Balors should be able to undercast in order for Dimensional Dervish to have any value. Who knows whether that's an accident where the GM has to tweak it so it works as obviously intended or it's intentional where Paizo assumed undercasting was a given...
IMO, it seems straightforward that a caster could undercast, especially for things like Wild Shape. Greater mastery (or power if one prefers) shouldn't lead to losing abilities.
What about casting a 5th level Magic aura on yourself, so that that would have to be countered before a different illusion would even be detectable?
That's not really an option for any group that strictly enforces the Uncommon trait.