# Can a Rod of Absorption absorb cantrips?

A Rod of Absorption enables the user to absorb incoming single-target spells as a reaction and store those spell levels for later use:

While holding this rod, you can use your reaction to absorb a spell that is targeting only you and not with an area of effect. The absorbed spell's effect is canceled, and the spell's energy -- not the spell itself -- is stored in the rod. The energy has the same level as the spell when it was cast. The rod can absorb and store up to 50 levels of energy over the course of its existence. Once the rod absorbs 50 levels of energy, it can't absorb more. If you are targeted by a spell that the rod can't store, the rod has no effect on that spell.

Given that cantrips are considered level 0 spells, is it possible to absorb a cantrip using the Rod? Or does a level 0 spell count as "a spell that the rod can't store"?

(Presumably, if this is possible, doing so would not store any additional levels into the rod, but would negate the cantrip's effect.)

• Commented Jan 25, 2021 at 5:15
• Green check or nah? Let me know if you would like to see anything else out of the answer. Commented Feb 2, 2021 at 13:50

### Yes, but they do not add to the Rod’s energy.

The Rod of Absorption says:

While holding this rod, you can use your reaction to absorb a spell that is targeting only you and not with an area of effect.

We observe in the rules for spellcasting that cantrips are spells:

A cantrip is a spell... A cantrip's spell level is 0.

Cantrips are spells, so they are valid for use with the Rod of Absorption, but add 0 levels of energy to the Rod each time it absorbs a cantrip, since a cantrip’s spell level is 0.

### It may not be feasible to use your Rod only for cantrips.

It sounds like a good idea at first, using the Rod only to absorb cantrips. But this probably isn't entirely feasible. If your DM just announces what spells the NPCs are casting, and is cool with you just cancelling them with your Rod, then it should work. But if you're going to try to do this at my table, I'm going to stop saying, "The enemy wizard is going to cast firebolt at you", and will rather describe the spellcasting. Then, if you want to try to use the Rod for cantrips, I will use the optional rules from Xanathar's Guide to Everything for Perceiving a Caster at Work:

Sometimes a character wants to identify a spell that someone else is casting or that was already cast. To do so, a character can use their reaction to identify a spell as it’s being cast, or they can use an action on their turn to identify a spell by its effect after it is cast.

If the character perceived the casting, the spell’s effect, or both, the character can make an Intelligence (Arcana) check with the reaction or action. The DC equals 15 + the spell’s level. If the spell is cast as a class spell and the character is a member of that class, the check is made with advantage. For example, if the spellcaster casts a spell as a cleric, another cleric has advantage on the check to identify the spell. Some spells aren’t associated with any class when they’re cast, such as when a monster uses its Innate Spellcasting trait.

This Intelligence (Arcana) check represents the fact that identifying a spell requires a quick mind and familiarity with the theory and practice of casting. This is true even for a character whose spellcasting ability is Wisdom or Charisma. Being able to cast spells doesn’t by itself make you adept at deducing exactly what others are doing when they cast their spells.

So using your Rod only for cantrips would probably not be feasible at my table. It would at least cost your reaction and wouldn't succeed all the time.

### After the Rod is full, it becomes the Rod of Cantrip Busting

Once the Rod is full, there is nothing to prevent it from still absorbing cantrips. The description says:

The rod can absorb and store up to 50 levels of energy over the course of its existence. Once the rod absorbs 50 levels of energy, it can't absorb more.

It says you cannot store more energy, not that it can no longer absorb spells. Since a level 0 spell stores 0 levels of energy, it probably still works.

### There is an alternate interpretation that invalidates all of this.

The description does say:

If you are targeted by a spell that the rod can't store, the rod has no effect on that spell.

One could arguably understand this to mean that a 0 level spell is a spell the rod cannot store. Take this way, cantrips would actually never work with the Rod of Absorption.

• Not sure if this is RAI, but RAW I think you could still use the Rod even after it has absorbed 50 energy. Mind you, you're using your reaction on something that isn't guaranteed to work, since you don't necessary know if the spell is a cantrip. Commented Jan 25, 2021 at 19:49
• @Brian You're right, that does work. Commented Jan 25, 2021 at 19:50
• @Brian Excellent point about not knowing ahead of time the level of spell you're trying to absorb. Commented Jan 25, 2021 at 19:57
• Hmm, actually, I've been thinking about this some more, and I think it's possible you actually do have at least some information about the spell, because you can only use your reaction to absorb a spell that satisfies certain conditions. I think the exact timing of this reaction and how much the user knows when making their decision should probably be a subject of another question. Commented Jan 26, 2021 at 0:22
• Wild ride with the last, alternative interpretation which I'd say is RAW as well lol. I'd rule with that interpretation tho Commented Jan 26, 2021 at 13:12