Is the “Bone of Animation” in Mordenkainen’s Tome of Marvelous Magic unbalanced?


I’m running Descent into Avernus.

In a session 0 for one my PCs, they acquired a Bone of Animation, which is an item in Mordenkainen’s Tome of Marvelous Magic.

(This is a pretty great list of magical items on dmsguild: https://www.dmsguild.com/product/291001/Mordenkainens-Tome-of-Marvelous-Magic)

BONE OF ANIMATION

Wondrous item, uncommon (requires attunement)

This item appears to be a regular human upper arm bone. While holding the bone you can use an action to speak the command word and turn the bone into a skeleton. The skeleton reverts to bone form after 1 hour or when it drops to 0 hit points.

The skeleton is friendly to you and your companions for the duration. Roll initiative for the skeleton, which has its own turns. It obeys any verbal commands that you issue to it (no action required by you). If you don’t issue any commands to the skeleton, it defends itself from hostile creatures but otherwise takes no actions.

Once the bone is used, it can’t be used again until the next dawn.

So far, so good. This is a pretty cool item.

We’re now approaching level 5, and my wizard is super excited to use Animate Dead when he levels:

This spell creates an undead servant. … On each of your turns, you can use a bonus action to mentally command any creature you made with this spell if the creature is within 60 feet of you (if you control multiple creatures, you can command any or all of them at the same time, issuing the same command to each one). You decide what action the creature will take and where it will move during its next turn, or you can issue a general command, such as to guard a particular chamber or corridor. If you issue no commands, the creature only defends itself against hostile creatures… The creature is under your control for 24 hours, after which it stops obeying any command you’ve given it. To maintain control of the creature for another 24 hours, you must cast this spell on the creature again before the current 24-hour period ends. This use of the spell reasserts your control over up to four creatures you have animated with this spell, rather than animating a new one.

By comparison to this, the Bone of Animation seems overpowered:

  • It does not require a spell slot to use
  • You can issue verbal commands without using an action

Whereas for Animate Dead:

  • You must expend a spell slot
  • You have to use a bonus action to command the creatures

The only downsides of the Bone is that you can use it only once per day, and the skeleton lasts for at most one hour. But in a typical adventuring day, there is probably one combat encounter that would require pulling out all the stops — so neither of these downsides seems that impactful.

I do understand that Animate Dead scales well, and at higher casting levels you can start to control groups of undead. But it seems very off to me that Animate Dead requires a bonus action to command, whereas the Bone does not. Every similar item in the Tome of Marvelous Magic is the same, so I assume it was a deliberate decision by authors.

The question I need an answer to:

I’m thinking of editing the Bone so that it also requires a bonus action to command. Without this I anticipate my wizard asking me why he has to expend a bonus action when my other PC does not.

Does this modification negatively impact game play or materially change the balance implications for this item?