The situation is this:
A Genie Warlock comes up with an elaborate scheme relying on multiple uses of his Mystic Arcanum; Wish. They know that this can be only cast once a day, but the wizard gave them a hint that just might double their efforts… Wishing for a simulacrum!!!
The simulacrum spell states: (emphasis my own)
The simulacrum lacks the ability to learn or become more powerful, so
it never increases its level or other abilities, nor can it regain
expended spell slots.
While the Mystic Arcanum states: (emphasis my own)
You can cast your arcanum spell once without expending a spell
slot. You must finish a long rest before you can do so again.
And, for lesser wishes, the Limited Wish feature states: (emphasis my own)
You entreat your patron to grant you a small wish. As an action, you
can speak your desire to your Genie's Vessel, requesting the effect of
one spell that is 6th level or lower and has a casting time of 1
action. The spell can be from any class's spell list, and you don't
need to meet the requirements in that spell, including costly
components; the spell simply takes effect as part of this action.Once you use this feature, you can't use it again until you finish 1d4 long rests.
Does this mean that the Simulacrum will also regain the use of Limited Wish and the Mystic Arcanum as well, given that they don't require spell slots? If so, what is to stop a Simulacrum from wishing for a simulacrum?
Best Answer
As written, a warlock's simulacrum regains their Mystic Arcanum spells each day.
As you have observed, the text of simulacrum is quite specific:
Mystic Arcanum is just a class feature, it does not use spell slots, so as written, nothing seems to prevent a warlock simulacrum from regaining use of their Mystic Arcanum spells each day.
That said, it seems perfectly reasonable to rule that Mystic Arcana do not recharge, just as spell slots do not recharge. If you intend to rule this way, this is something you should discuss with your warlock early, so that they do not make any build decisions based on the assumption that a simulacrum will be able to recharge Mystic Arcana.
An army of simulacra is not a new exploit.
The accepted answer to this question outlines how an army of simulacra can be created by any character with wish and simulacrum. Ladifas writes:
And yes, it is game breaking, which is why, as Ladifas notes above, it is outright banned in Adventurer's League play.