Can I use my familiar from the Find Familiar spell as a safety deposit box?

Question

The Find Familiar spell states, in part:

As an action, you can temporarily dismiss your familiar. It disappears into a pocket dimension where it awaits your summons.

The question arising from this is:

1. Is this pocket dimension different for every familiar in the world? Thus being a personal pocket dimension?
2. If this is true, then it should be able to store items given by its master for safe keeping away from anyone else, as long as these are items that a familiar could carry with it. Can the familiar bring small items with it into the pocket dimension for safe keeping?

Answer 1

So, to your first question: The pocket dimension will be unique to your familiar.

While it's difficult to prove this, a dimension that potentially contains the familiars of every spellcaster with the Find Familiar spell in the entire universe at the same time really doesn't sound like a "pocket" dimension.

Also, what would happen if a Wizard sent his familiar to the pocket dimension at the same time as the vastly more powerful familiar of his Warlock nemesis? You have to assume that the Wizard probably wouldn't ever see his familiar again, if you see what I mean.

To your second question: RAW, the familiar probably can't take items with it.

The spell says you dismiss your familiar, not your familiar and everything they're carrying. Similarly, "it" disappears into a pocket dimension - "it" here definitely refers to your familiar, there's no reason why it would mean "your familiar and everything it is holding". It's also worth mentioning that your familiar is defined as a spirit that takes the form of an animal - so maybe it could take spirit objects with it, but probably not physical ones.

Additionally, when asked a similar question for Find Steed, Crawford said that the steed should leave gear behind. While Find Steed is different to Find Familiar, its wording with respect to this issue is similar, so the same rules probably apply.

On the other hand, Mearls says he'd allow it, but only for a few minutes. The usual caveat applies here, of course: Mearls is not a source of official rules interpretation, just a source of how he would rule things in his game. So you can pretty much take or leave his advice as you choose.

Answer 2

Your first question is a classic example of the kind of thing GMs made different rulings on, back in the day, and those different rulings led to different campaign worlds. The second question is similar to the first one, but I expect most GMs will be okay with the familiar carrying a small amount of stuff (a signature hat, for example) into the pocket dimension, while some will let it carry whatever it feels like and even drop it off in the other dimension, or bring unexpected things back, and others won't let anything through at all.

If you're a player, the answer is ask your DM

If you're a DM, the answer is ask your players, by which I mean whatever makes the game world the kind of world they want to play in and you want to DM.

The "All familiars go to the universal familiar break room, which is why they sometimes show up with travel cups of brimstone-infused espresso or celestial cucumber slices on their eyes. They can take your stuff, but they'll probably pawn it by the time you call them back" answer is more Blackmoor, the "Familiars are otherworldly spirits which disincorporate into their true form when they leave the physical world. They cannot take physical objects with them, unless those physical objects are also mystically disincorporated in the proper manner, which must be researched and depends upon the specific nature of the familiar to carry the object" answer is more Greyhawk.

Answer 3

Sprites can be familiars under the Warlock's Pact of Chain (PHB. 107).

Sprites wear leather armor, carry a shortbow and longsword (MM. 283) -- since these are "part" of the sprite description and equipment, I'd venture to guess that other items it carries would be carried with it -- "it disappears, leaving behind no physical form."

I'd argue if the familiar is carrying it on their person, and isn't over encumbered, it is taken with them. That said, I can see how some DMs would rule otherwise, based only on the wording of the spell; but I think RAI, especially given the sprite, is that they take their junk with them.

Answer 4

UPDATE

As of the latest Sage Advice Compendium, familiars cannot take any items with them.

[NEW] When you dismiss the familiar you conjure with the find familiar spell to its pocket dimension, can it take any objects it’s wearing or carrying with it? No, the intent of find familiar is that any objects are left behind when the familiar vanishes. This intent will be reflected in future printings of the Player’s Handbook.

This is from version 2.5, October 2020