How do the Spirit Guardians and Sanctuary spells interact?

Question

A player in my group asked the DM:

1. What if Cleric 1 was to cast spirit guardians and go for the heart of battle
2. Then Cleric 2 cast sanctuary on him
3. Then Cleric 1 just sits there not actively attacking, probably taking the Dodge action while keeping concentration on his spell.

This makes it OP because he would be sitting there dishing out massive damage, while enemies would have to make a DC 15 Wisdom saving throw to hit him, and if they actually succeed they would have to hit with disadvantage due to the Dodge action.

The crucial point lies in the wording of sanctuary:

If the warded creature makes an attack or casts a spell that affects an enemy creature, this spell ends.

Cleric 1 cast spirit guardians before sanctuary came into effect, so he will not attack or cast something for the time being; he just sits there.
But he is also keeping concentration on a spell that harms others.
What do you think? Does the sanctuary spell end or not?

Answer 1

As of the 2018 errata, if an enemy takes damage from your spirit guardians spell, your sanctuary spell ends

The description of the sanctuary spell (PHB, p. 272) originally said:

If the warded creature makes an attack or casts a spell that affects an enemy creature, this spell ends.

However, the 2018 PHB errata added "deals damage to another creature" to the list of conditions that end the sanctuary spell. The description of the sanctuary spell now reads (emphasis mine):

If the warded creature makes an attack, casts a spell that affects an enemy, or deals damage to another creature, this spell ends.

Even though the spirit guardians spell doesn't directly affect an enemy creature when cast, it does deal damage to them:

An affected creature's speed is halved in the area, and when the creature enters the area for the first time on a turn or starts its turn there, it must make a Wisdom saving throw. On a failed save, the creature takes 3d8 radiant damage (if you are good or neutral) or 3d8 necrotic damage (if you are evil). On a successful save, the creature takes half as much damage.

As a result, the sanctuary spell ends as soon as an enemy takes damage from a spirit guardians spell cast by the warded creature.

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Even before the 2018 errata, the intent was that damaging an enemy would end the spell (though this was not reflected in the description of the spell). In an unofficial tweet in July 2016, rules designer Jeremy Crawford stated:

You first cast spirit guardians and then sanctuary. Does sanctuary end when spirit guardians deals damage to enemies?

RAW: Sanctuary isn't stopped if an already-cast spell deals damage. RAI: A damaging activity ends the spell.

RAI means errata or a future edition would possibly change RAW, right? Thanks for the answer

That's correct

Clearly, the 2018 PHB errata changed the spell so that it now works as intended.

Answer 2

The rules are pretty clear. You don't break Sanctuary unless you make an attack or cast a spell that affects an enemy.

As for it being OP, you're making a cleric not attack enemies or cast offensive spells, to maintain Spirit Guardians. It's not massive damage, and given that the cleric using it is doing nothing else, enemies don't even have any reason to go near them. Sure, that cleric is hard to attack, but enemies have no reason to attack them, and every reason to attack every other member of the party. If for some reason you really don't want that specific cleric to be attacked, this becomes useful. But if you compare it to the cleric using Spiritual Guardians, Spiritual Weapon, and using his action every turn, his usefulness as a character doesn't measure up.

Spirit Guardians, like several other spells, is a powerful spell because you can keep doing other things while you use it. It adds a bit of ongoing damage, and in a long battle you get a lot of damage for a minimal resource investment. Using it like this, you're putting in a lot of resources for not all that much damage.

Answer 3

The relevant part of the description of the sanctuary spell reads:

If the warded creature makes an attack or casts a spell that affects an enemy creature, this spell ends.

Part of the description of the spirit guardians spell reads:

When you cast this spell, you can designate any number of creatures you can see to be unaffected by it. An affected creature’s speed is halved in the area, and when the creature enters the area for the first time on a turn or starts its turn there, it must make a Wisdom saving throw. On a failed save, the creature takes 3d8 radiant damage (if you are good or neutral) or 3d8 necrotic damage (if you are evil). On a successful save, the creature takes half as much damage.

So if Cleric 1's Spirit Guardians affects an enemy creature (which happens as soon as an enemy moves into it), then Sanctuary on Cleric 1 ends.

As a person that has been a D&D cleric for a very long time, I would love to have a good argument to give the DM as to how I can accomplish affecting the enemy while maintaining Sanctuary. No DM I have ever played with would ever allow such a thing.