This question is inspired by Dale M's answer to another question. In that answer, Dale M said (bold added):
So if a Simulacrum of a cleric can take a long rest it can change its prepared spells. Maybe you need to ask if they can take a long rest?
Now, at first I wasn't going to ask that question: it seemed unambiguous to me that a simulacrum copy of a humanoid could take a long rest, especially since the rules on resting (post errata) state (PHB, p. 186, bold added):
Adventurers, as well as other creatures, can take short rests in the midst of a day and a long rest to end it.
But Dale M's answer got me wondering. Is there something about the simulacrum copy I'm not considering? For example, post errata, it has been clarified that a simulacrum of a humanoid is a construct (PHB, p. 276). And an errata has also clarified that (PHB, p. 186, bold added):
A long rest is a period of extended downtime, at least 8 hours long, during which a character sleeps for at least 6 hours…
With all these errata available, I found myself suddenly uncertain. I wasn't sure if constructs could sleep (I assume they can, since no rule I've seen has said otherwise, but perhaps I missed a rule somewhere), or if there was some other rule that would stop a simulacrum copy form gaining a long rest.
Now of course, a simulacrum can't gain some of the major benefits of a long rest. It definitely won't regain spell slots, and (at least by “Rules as Intended”), it wouldn't regain hit points from a long rest. But for the purposes of class features other than these which recharge on a long rest, I'm still curious about the answer.
So what does the community think? If the spell Simulacrum copies a humanoid (which was capable of taking a long rest itself), can this construct copy take a long rest?
Best Answer
There is no reason a simulacrum cannot sleep or take a long rest.
The spell description for simulacrum states:
So mechanically, the simulacrum is identical to the original, except its creature type is "construct". Are there any properties inherent to being a construct? No:
Being a construct does not by itself imply anything about the simulacrum. It changes how other features interact with the simulacrum, such as certain spells not being able to affect constructs, but creature types have no rules of their own. Do the rules for long rests mention the construct creature type? No:
There is nothing in the rules that prevents a simulacrum from taking a long rest, so a simulacrum may take a long rest.
There are constructs with abilities and features that interact with long rests.
Consider the bronze scout from Mordenkainen's Tome of Foes; it has an ability that recharges on a long rest:
For another example, see the Clockwork Kraken from Lost Laboratory of Kwalish:
There are numerous other examples of constructs which have features and abilities that depend on taking a long rest. If these constructs could not take long rests, none of these features would make sense.
Alternatively, we can also observe numerous constructs with the Unusual Nature feature:
This feature clearly assumes that such a construct can take a long rest, but that they do not regain hit points and hit dice when doing so.
From these examples, it is clear that apart from an explicit statement that a particular construct cannot take a long rest, the rules are assuming that constructs can, in general, take a long rest.