Can Meld to Stone be used with Offensive Spells?

Question

Suppose my character is locked in a jail cell with several of their worst enemies, none of whom have any spell-casting abilities. (Assume the character has retained their holy symbol for spell-casting.) As a cleric, they assess the situation, and quickly cast Meld into Stone on the stone floor of the jail cell, then cast Spirit Guardians, which targets self. (Alternately, they might cast Spiritual Weapon before casting Meld into Stone).

1. Does this work? Can the Spirit Guardians spell penetrate the stone and can my character continue to use their Spiritual Weapon after entering the stone?
2. Aside from attacking the stone, calling the guards/fleeing, or a highly improbable hat-trick of some kind, do the enemies (who aren't spell-casters) have any clear options in this situation?

I suspect that, as with this related question, the answer is that there is no rule that forbids this, so it is largely up to the DM, but I'm wondering if there are rules that forbid this that I have overlooked.

Answer 1

The answer depends on one thing: do you have total cover while melded?

The rules for Areas of Effect state:

A spell’s effect expands in straight lines from the point of origin. If no unblocked straight line extends from the point of origin to a location within the area of effect, that location isn’t included in the spell’s area. To block one of these imaginary lines, an obstruction must provide total cover, as explained in chapter 9.

Ergo, if the caster has total cover with respect to the outside world while melded into stone, then the area of effect of spirit guardians will be suppressed. Meld into stone states:

You step into a stone object or surface large enough to fully contain your body, melding yourself and all the equipment you carry with the stone for the duration. Using your movement, you step into the stone at a point you can touch. Nothing of your presence remains visible or otherwise detectable by nonmagical senses.

While merged with the stone, you can't see what occurs outside it, and any Wisdom (Perception) checks you make to hear sounds outside it are made with disadvantage.

So the questions is: does the description of meld into stone mean we have total cover? It does not explicitly say that we have total cover, but it does not have to if the effect falls under the definition of total cover. Let's check that:

A target has total cover if it is completely concealed by an obstacle.

Unfortunately, this doesn't get us to a clear conclusion. Is there stone between you and the outside, or are you the stone that is exposed? This is what the spell and rules do not tell us, but this is what we need to know to answer this question about spirit guardians.

The DM must decide.

Answer 2

Ask your DM

The area of effect rules for spells (p. 204 PHB) state:

A spell’s effect expands in straight lines from the point of origin. If no unblocked straight line extends from the point of origin to a location within the area of effect, that location isn’t included in the spell’s area. To block one of these imaginary lines, an obstruction must provide total cover, as explained in chapter 9.

It is not entirely clear if you are behind cover, or if you are melded with the cover -- your DM has to decide this.

Ongoing area effects very likely also need line of effect from their source to work (although it is not airtight, so your DM may rule differently). This means that once you step into the stone, the Spirit Guardians will be suppressed, unless your DM rules you are one with the covering stone.

Spiritual Weapon likely also needs line of effect to be operated, although it is even less clear-cut. Again, up to your DM.

Even if your DM rules you can use it, you cannot see your opponents and have disadvantage to Wisdom (Perception). This means you need to locate them by ear and if they succeed in a Dexterity (Stealth) check to hide or sneak against your perception, would need to guess where to attack. As you are effectively blinded, those attacks then also would have disadvantage.

Answer 3

Yeah, this should work. Meld into Stone explicitly says you can cast spells on yourself, so Spirit Guardians is a legal option, and you're still at your old location (since you can't move). So the Guardians will continue to pummel targets. Keep in mind though the Spirit Guardians lets you exclude "any number of creatures you can see" when you cast it, and since you can't see when using Meld into Stone, it means your guardians will indiscriminately destroy everything in the jail cell if you cast it after melding. Not a good idea if you've got friends locked up with you.

In this situation, non-spellcasters who can't move far enough probably don't have any realistic options to stop you and will just die. Their only potential option is dealing enough damage to the stone to eject you, but especially in a prison that's not really likely to work, it'd likely require tools or magic.

Likewise you can cast Spiritual Weapon before melding and then keep attacking with it. However, since you can't see and you make Perception checks to listen with disadvantage, in this case any other enemies in the cell might try to make Dexterity (Stealth) checks to try and hide from you, and they're likely to succeed. At that point you'll have to guess their location and probably won't be able to hurt them.

Also, if you cast Spiritual Weapon then you cannot meld on the same turn, since you can't cast another non-cantrip spell when you use your Bonus Action to cast a spell.