If I cast imprisonment on myself with the Minimus Containment option, can I just never be attacked and spam Sacred Flame from my levitating diamond (via Spell Mastery Levitate)?
Or for a more exact question, are there any ways barring Dispel Magic to kill a creature in Minimus Containment?
Related questions (which I'm not re-asking about here):
First, you'd have to fail the Wisdom saving throw, which RAW you can't just choose to do. If you manage to fail the save, barring the spell being dispelled. You are almost unkillable from anything that tries to pass through the cage.
The target shrinks to a height of 1 inch and is imprisoned inside a gemstone or similar object. Light can pass through the gemstone normally (allowing the target to see out and other creatures to see in), but nothing else can pass through, even by means of teleportation or planar travel. The gemstone can’t be cut or broken while the spell remains in effect.
Jeremy Crawford ruled that Sacred Flame doesn't require a clear path to the target on Dragon Talk from 1/19/17 at 36:20. Not because of the line of sight, but because it states in the spell that it ignores cover. So, by an official ruling, you could be Sacred Flamed from inside the gemstone.
Even with the ruling, I'm not convinced many DMs would allow sacred flame to be cast through the gemstone. The specifics of the spell imply an intent that magic of any kind can't pass through the prison. So, I'm not sure if it would still rain fire from heaven.
If your DM does allow you to sacred flame from inside, then they should allow the spell both ways. Moreover, any spell that allows you to ignore cover would also be allowed to pass into the gemstone using the same loophole you're attempting to use. Moreover, a DM might rule that you are restrained by the spell, which would mean:
- A restrained creature’s speed becomes 0, and it can’t benefit from any bonus to its speed.
- Attack rolls against the creature have advantage, and the creature’s Attack rolls have disadvantage.
- The creature has disadvantage on Dexterity saving throws.
Which would also mean you'd be unable to dodge very well.
I think the RAW might allow you to levitate the Gem, but I'm not sure most DM would let make the Gem levitate, either.
The plan comes with one quick easy foil:
A creature you can see
The target can move only by pushing or pulling against a fixed object or surface within reach (such as a wall or a ceiling)
No risk of death, but you're out of the fight until you get dispelled.
Nothing about the Minimus Containment effect suggests the barrier is one-way, or in fact behaves any differently for effects originating from within it than effects originating from without. Consequently, any spell the caster can use to affect the world outside the gem can be used on its inhabitant.
Crawford's logic for allowing Sacred Flame to avoid path-of-effect targeting restrictions appears to be that...
In point of fact, these are the same condition; the text for Sacred Flame merely serves as an explicit reminder of this portion of the cover rules:
A target can benefit from cover only when an attack or other effect originates on the opposite side of the cover.
The following spells satisfy this condition as well:
Holding the logic that allows the casting of Sacred Flame, any of these could be used to kill you within the gem (or used by you on targets outside of it). In addition, most effects reliant on Wisdom save that specify they target "any creature you see within range" also seem to fit.
And the reasons for both are related.
From the PHB p.204 under Targets: "To target something, you must have a clear path to it, ...". Because "... nothing else can pass through ..." you do not have a clear path and so most spells cannot be targeted from inside to outside or vice-versa.
However, Sacred Flame has a specific rule that overrides the general one, it targets "a creature that you can see". This mechanic is not that unusual: it includes a number of class features and quite a few spells. You would be susceptible to any and all of these.
However, spells like Sunburst will affect you if you are in its area of effect. It says "Brilliant sunlight flashes in a 60-foot radius centered on a point you choose within range. Each creature in that light must ..." Since the gem does not stop the light, you are in it and will suffer its affects.
