As a junior wizard, you need to carry around a lot a paraphernalia - scrolls, tomes, potions, stones, and many other things. Fortunately the Wizarding 102 class included the creation of pocket dimensions. And so begins your quest to make a usable bag of holding.

There's just one problem: the only pocket dimensions you can make are big, really big. The inside of your satchel isn't just bigger than it looks, it's lightyears across in there! So if you simply toss an item into your bag it's going to drift away from arms reach of the opening fairly rapidly.

One mage suggested attaching items with strings to the opening. This allows you to store a lot of stuff, but then getting things out is fiddly. Another mage suggested building a shelf inside the bag, but that limits the amount of stuff quite a lot.

So, how do you do it? How do you ensure that you can access items inside your pocket dimensions without needing to use telekinesis to retrieve objects from kilometers away?

You want:

  • To be able to retrieve items quickly. When attacked by the Beast of Baltoth you need to be able to get at your potion of flame very rapdily.
  • To be able to store items quickly without losing them.
  • To be able to store large items such as swords and delta class summoning stones.
  • To be able to store small items (eg a 1cm sphere of sunstone)
  • To be able to store lots of things - ideally your whole alchemy setup.

There are some problems with large pocket dimensions we are going to ignore. These include:

  • The fact that the pocket dimension (upon opening) would inhale the atmosphere of earth if it wasn't already filled with air.
  • The fact that if the pocket dimension was filled with air it would coalesce into stars and galaxies.

Other thoughts:

  • You can decide if there is gravity or not inside the pocket dimension, and which way it points.
  • The opening of the pocket dimension is attached to a satchel. You can safely leave things poking through the opening and attach things to the outside of the satchel.
  • I'd rather avoid "spell each item such that it comes to your hand when you want" and "play fetch with your familiar"
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    $\begingroup$ Then you would have a satchel with a pocket dimension inside your satchel with a pocket dimension. This is perfectly permissible. A pocket dimension is literally another universe. It's universes all the way down :) $\endgroup$
    – sdfgeoff
    Commented Aug 10, 2021 at 11:47
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    $\begingroup$ :) I ask because in some game systems, if you do this, you get a boom. A very big boom. $\endgroup$ Commented Aug 10, 2021 at 12:03
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    $\begingroup$ It's a mistake to assume that the interface between the bag's opening and the dimension(s) is stable. At least in the real world, there are no absolute frames of reference. Given that magic opened this portal at one point, why is the magic limited to opening it at exactly one spot? Maybe the opening drifts too, or is even controllable where it drifts. Thus, it can open to within an arm's length of where he wants it every time he uses it. $\endgroup$
    – John O
    Commented Aug 10, 2021 at 13:26
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    $\begingroup$ "it would coalesce into stars and galaxies" - what is expected service life of pocket dimension, should wizard care about this distant future? $\endgroup$
    – Alexander
    Commented Aug 10, 2021 at 16:50
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    $\begingroup$ @Alexander That's all we need, planned obsolescence from wizards. "Oh, he'll never use this dragon for more than 3 years anyway and then it will be a trade-in for a much larger behemoth...". I can see it now, some vengeance quest from the race of people trapped in a 3 billion year old change purse universe because the manufacturer only expected and cared about the product for its 5 year planned service life. $\endgroup$
    – John O
    Commented Aug 11, 2021 at 14:11

13 Answers 13


Inside the bag is a town of fairy creatures, they live happily and safely, maintaining the vast vaults and libraries of the town. In the center of the town is a richly decorated raised platform. Every so often fiery arcane runes appear in sky spelling out the name of some item that the wizard needs. The creatures run to quickly retrieve the item from the depths of the vaults and placed on the platform, before the sky tears open with a thunderous crash and a giant wizard's hand descends to retrieve the item. Thankfully time runs faster inside this dimension, so the denizens have plenty of time to retrieve the items.

Alternately, instead of a fey town the bag is a mess of industrial corridors and barred cages, inhabited by enslaved demons. Or a network of interwoven tunnels inhabited by goblins.

  • 5
    $\begingroup$ Storage fairies, driving fork-hoists. Quick, I need a memesmith! $\endgroup$
    – Corey
    Commented Aug 11, 2021 at 3:56
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    $\begingroup$ Downside: the wizard's hand comes out of the pocket dimension somewhat oxygen-starved, due to the time dilation and blood flow. $\endgroup$
    – wizzwizz4
    Commented Aug 11, 2021 at 13:56
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    $\begingroup$ Honestly based on this answer, I'd find the story of the world inside the wizard's bag to be a much more interesting one than the story of the wizard holding the bag. $\endgroup$
    – Lou
    Commented Aug 12, 2021 at 8:59
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    $\begingroup$ @Lou I'm picturing a harried fairy quartermaster going "the Circlet of Human Perfection AGAIN?? It's the 10th time this week, you should be going to a psionic to sort through your confidence issues" $\endgroup$ Commented Aug 12, 2021 at 10:02
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    $\begingroup$ @JulianaKarasawaSouza Yup, or the episode of Rick and Morty where Rick has created a micro-universe inside his car battery which exists solely to power his battery, and within that micro-universe they've created another micro-universe, and so on. $\endgroup$
    – Lou
    Commented Aug 12, 2021 at 10:14

That's a good question, young acolyte. One that mages have been asking ever since Magister Lanaken first formalized the dimensional storage techniques. For a full discussion on the thaumaturgic explanation I'll direct you to Kenshian's 'Dimensional Theory' - third edition, by preference.

Briefly however, the apparently unlimited space accessible to us through dimensional storage magic is not the same as the world we experience. Broadly speaking the rules that we work by in our daily lives have no relevance to the storage spaces. Size, mass, speed, pressure... none of them have the same meaning within the storage space as they do in the natural world.

According to Kenshian it may be incorrect to call it a space at all. In her model she treats these storage dimensions as conceptual regions rather than physical ones. This certainly explains a number of things that have befuddled mages much more experienced that you or I. Let's run through some of the common questions shall we?

Why are storage spaces so large?

Simply put, they're not. Size does not exist in a dimensional store, so it is neither large nor small. The aperture, the connection between your storage space and our world, is a thaumic construct which performs a simple translation between the two. As you pass an object through the aperture it assumes the properties of objects in the storage space. If Kenshian's model is correct then objects are translated to conceptual objects, without any physical properties. They occupy no space, have no location, no mass.

Considering the sheer amount of stuff my own storage space contains, I'm rather glad that is the case.

How do we access objects when we need them?

Just like the aperture transforms the properties of objects, it also transforms your will through the same mechanism. When you reach into the space to remove a potion for instance, your will is impressed on the conceptual space. The concept of your hand, guided by your will, simply grasps the concept of the potion. If no potion concept exists within the space then you'll fail. If your will is diffuse then it might grab the wrong potion. If I have fifty different potions in my store and I just reach for "a potion" then what I withdraw is, apparently, random. The better you define the specific object the more likely you are to retrieve that one item and not something similar.

I think we'll all agree that this is a fabulous boon compared to the older spatial storage techniques, where one would have to fumble around among the physical objects.

But we can't transform artifacts, how can they be stored?

Seems like a real problem, but when it comes to conceptual spaces it might not actually be relevant. The rules of a conceptual space simply apply to everything that enters them. We speak of the aperture as having a transformative effect on objects, but in reality it's just acting as an interface between the conceptual and physical. No physical thing can exist in a conceptual space, so any physical object - no matter how empowered, regardless of form - can only have conceptual properties within the space.

Gruent's treatise "Metaphysical Representations in the Realms" covers this in greater detail, with broader discussion on other types of spaces such as the so-called elemental planes.

If they're just concepts, why do they stay the same?

Honestly, Gruent does a much better job of explaining this. It's not my field.

The short form is that there's something that defines the object, and that something doesn't change just because the object moves to a conceptual space, an elemental space or a physical space. Gruent calls this the ontic form of the object. Moving between spaces doesn't alter the ontic form, only how that form is expressed within the rules of the object's reality - the space it occupies.

Why don't things cool or spoil when I store them for a long time?

Temperature, corruption, time itself? Your storage spaces contain none of these things. Not as we mean them anyway. Clearly there's something like time, since we can change the contents of the storage. But while there, objects don't experience the passage of time.

And before you ask, no, we can't store people. Or complex animals. Conceptual spaces appear to be compatible with the spiritual essence that distinguishes living creatures from dead ones. Passing into a conceptual space damages the spirit in direct proportion to the complexity of the spirit. An insect may pass into the space and emerge apparently unharmed, but it dies soon after. A cat emerges insane and dying. The last time a human trial was conducted the results were horrific enough to dissuade further experimentation.

Any creature with will is affected, except those whose spirit is attuned to certain esoteric spaces - some elementals for instance and most divine entities, although I don't suggest you try this without further study. Ensouled items are also unaffected, and report no experience within storage, as though they were immediately withdrawn regardless of how long they are stored.

And that's the end of today's session. Next week we'll cover some of the important caveats of using conceptual spaces, their limitations and the few non-living exceptions. I expect all of you to submit a medium essay - that's three full pages, Mr Druvek, without illustrations this time please - on the formation of storage spaces and maintenance of their physical anchors. With references to DuVrey, Ak'then'kar and Malcolm.

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    $\begingroup$ "If no potion concept exists within the space then you'll fail." That tingles my Pratchett senses. ;-) $\endgroup$
    – Pablo H
    Commented Aug 11, 2021 at 16:23
  • $\begingroup$ I dunno, I think the cat would be fine... ;) $\endgroup$
    – Cullub
    Commented Aug 11, 2021 at 16:38
  • $\begingroup$ @Cullub Perhaps if its name is Pixel... $\endgroup$
    – Corey
    Commented Aug 11, 2021 at 22:42
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    $\begingroup$ I love this explanation. It's basically hand-waving but in a way that sounds really cool and totally works for a magical universe. $\endgroup$
    – Lou
    Commented Aug 12, 2021 at 9:02
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    $\begingroup$ @Lou That's the beautiful thing about magical settings, you can throw all sorts of crazy junk in there behind the curtain and just nod vaguely in the direction of an explanation, and everyone lets it slide. Until you contradict yourself, of course, then they pick at every little inconsistency like vultures. $\endgroup$
    – Corey
    Commented Aug 12, 2021 at 9:09

Different dimension = different universe with different rules

Whenever some physical body is completely contained in the bag of holding, it becomes a LEGO version of itself. This reduces the size of the object considerably. The plane of existence inside the bag also contains an infinite LEGO board, to which most objects can be attached directly. When a mage gets such a bag, they would be wise to put on some pieces that will allow them to attach non-brick pieces (i.e.: a suit of armor would connect to the infinite board by the feet, and would be able to hold a sword in each hand).

Getting the item you desire becomes an exercise of feeling for what you want with your hand. Once you find it, you just have to pull it out. The object becomes a regular version of itself when getting close to the bag's opening.

This is what the inside of a bag could look like. Notice the blocks of gold, copper and water. There are also some plants to the right. Never mind the prisoners to the left.

A really big LEGO board with some pieces attached to it.


Your wizard will have to be really organized

Maybe your wizard can even get a side hustle of being a warehouse manager! Or creating a pocket-dimension organizing system that can be worked quickly to his (or even others') needs à la Marie Kondo

Groups of objects - urgent reach

The basic separation between the objects would be not by type or size but by how quickly they'll have to be retrieved when they're needed. For example, in your typical factory you have a LOT of safety equipment. Even though they're all the same "group" (so to say), some items like fire extinguishers, first aid kits, AEDs, eye washers need to be retrieved or reached very quickly when needed. Other items like harnesses, noise meters, etc. can be retrieved on a more leisurely pace

For urgent reach items, they should be kept within short distance of the opening - either attached to the opening of the satchel or tied to a short string with a tactile code so the wizard can find them by touch without needing to waste much time looking for them

Groups of object - not urgent reach

These objects are usually not immediately needed, so there is also more flexibility on how to store them. The wizard can opt for storing his alchemy setup all together in a large crate, so they can immediately pull it out, open the crate and use it

Causative's wheel idea would work nicely for this one, so would be a colored line system if you're still going with the string idea (which is a mimicry of the color line system used for hospital corridors and other large public buildings - for example, blue line means alchemy, so the alchemical items are stored in branching strings with labels).

The important thing here is to have an indexing system / list of contents so the wizard knows how to find each item


Make it like a directory structure, with pockets inside pockets.

The inside of the bag would look like one of those "organizer" bags that are advertised on late-night TV that have a place for everything.

Or, it might be more like an accordian file.

accordian file

When you open one of the leaves, it opens to fill the entire original size of the mouth, with the closed sides being pushed completely flat.

Inside that compartment, an inch down, is another accordion file.

You can open successive leaves to quickly get to the compartment you want. You can even label them along the edge.


Assuming zero G inside.

Solution 1: Wheels

  • Start with a circular wooden wheel. Attach items to the rim of the wheel. It would be ideal if you could glue magnets to the wheel and the items and just stick the items to it. Failing that, the wheel could have hooks or clips. To get the item you want, you reach in, rotate the wheel until the item you want is at the top, then remove that item.
  • The wheel stays in reach because it has hooks around its perimeter, and you don't let go of the wheel without hooking one of those hooks around the lip of the bag.
  • Take a second wooden wheel, just like the first, and join them with an axle so that they can rotate independently. Now, to get your item, you move the whole apparatus until the wheel you want is in reach, then rotate that wheel until you get the item you want.
  • Attach as many additional wheels to the axle as necessary.
  • Always remember to hook the nearest wheel around the lip of the bag, so the whole apparatus doesn't drift away.

The limit on how many items you can store this way is the mass of the apparatus. It becomes more difficult to move the whole thing if you have too many items, though zero G helps with that, and if the correct wheel is in reach you don't have to move the whole thing because the wheels can spin independently.

Solution 2: Board

Put a big piece of plywood in there, with the flat side facing the opening. Attach the items to the board. The board has handles on it that you can use to pan it left/right or "up"/"down", until you get to the item you want. The board also has hooks at regular intervals for hooking around the lip of the bag so you can keep it from drifting away.

Again the limit is how much mass you have to move to get to the item you want. The board solution is a lot simpler than the wheel and axle solution, and in total it would weigh a bit less, but with the board solution you always have to move the whole apparatus, while with the wheel solution sometimes it suffices to only move one wheel.

Solution three: Rods

Take a certain number of items and attach them to a straight rod, 3 feet long. The rod has a labeled hook at the end. You put the rod into the bag, hook it around the lip, and angle it way off to the side so it doesn't obstruct the opening. Now you have a few dozen hooks around the opening, for a few dozen rods. Inside the space, the rods are splayed out radially in the same plane as the opening. Select the rod you want based on the labels on the hooks, then pull that rod away from the side into the open area in the center, and pull it out. Then choose the item you want from the rod and put the rod back.

This solution doesn't require moving the whole apparatus, but there's a limited amount of space for rods to be arranged like this. Also, it's maybe a bit slower to use since you have to take the rod out of the bag to get the item.

Supplementary solution for rarely-used items: Bags.

Stuff that you won't need to retrieve quickly can be just thrown in big bags off to the side of the primary apparatus. This reduces the clutter among the items that are prepared for more rapid retrieval. The bags would be attached via strings to the outside.


Learn to Ensorcell a Smaller Universe
I mean really! Who needs 98.342 bajillion tetratic gigametres of space to keep a few essentials in!

If your magial student had actually paid attention in Wizarding 102, she'd have learnt that it's much easier to store things in a more reasonably sized bag of holding.

Just tweak the equation to redefine the outer boundary of the space within. V = 4/3 πr^3. Really, all she has to do is limit r to something reasonably smaller than ∞! Keep it somewhere between 1 and 2 yards and the insides won't be too difficult to rifle through without recourse to bound & impressed Imps to do the searching and retrieval!

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    $\begingroup$ It may actually be that an infinite universe is easier to make than a finite one. Think of it like making a program. When you create a cartesian system, it defaults to having no actually boundaries or limits. The edges of your space then need to be defined, and behaviors defined for what happens when you reach that limit. Sure, Master Wizards have the skill for this, but apprentices have to practice with infinite universes first before they try anything as advanced as constraints. $\endgroup$
    – Nosajimiki
    Commented Aug 11, 2021 at 18:11
  • $\begingroup$ @Nosajimiki -- Oh I concur! There is in a world far far away, after all, a thaumaturge by the name of Mastar Crandall who first described the magic necessary to make a pocket universe. Sadly the experiments went awry and Master Crandall ended up with a universe the exact size and shape of the universe. Folks watched with fascination as their doppelgangers approached, similarly astonished, and the new universe settled into the same space and time. People afterwards are said to have been beside themselves with astonishment. Azor Ramujjan, in the late 1200s, was the thaumic artificer who... $\endgroup$
    – elemtilas
    Commented Aug 12, 2021 at 0:36
  • $\begingroup$ (cont)... more than describing a new kind of magic actually circumscribed it. He devised a way to get the cartesiae to circle back on their point of origin, thus creating a self contained and rather more handily sized pocket universe. It was still vast, and the thaumics were often built into large wardrobes through the door of which one could enter their private universe. Anymore, of course, arithmancers have determined how to rein in the expanse of the cartesiae, allowing the crafting of ever smaller universes. You're correct: definitely not work suitable for young students! $\endgroup$
    – elemtilas
    Commented Aug 12, 2021 at 0:41
  • $\begingroup$ The development of smaller bags of holding might become a feature of the story. Why is Manba? always so crazy prepared. And why does xe have so many different bags of holding? $\endgroup$
    – Jontia
    Commented Aug 12, 2021 at 21:38
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    $\begingroup$ @Jontia -- Oh! You mean they? I'm not too familiar with Batman, but yes, he seems to be crazy prepared for any situation any supervillain throws his way! $\endgroup$
    – elemtilas
    Commented Aug 14, 2021 at 2:11

Robe of Many Pockets

... something like this: but more wizardly ...

enter image description here

One of the hard things about using the same bag to hold everything is that some things are just on very different scale than others, and the solution that works for one sort of thing does not work for another. Sometimes you just need an easy access place to hold a few tiny vials of pixie dust, and in others you need to hold a suit of plate armor.

The good news is that spinning up new pocket dimensions seems to be pretty trivial in your setting; so, there is no reason to settle for one "catch all" pocket dimension. By having many pockets attached to many pocket dimensions, you can solve each problem independently of one another.

Your potions for example may have a pocket that opens up to a sort of vending machine into another dimension, so you open the pocket, pull out a potion, and another one just slides down or is pushed into its place. Then you have your wizard's staff which is long and skinny; so, you have one small pocket that leads to a long narrow tube perfectly sized for it. Takes up very little real-estate on the outside of your robe, and it makes getting to your staff really quick and easy.

Since we are going with a robe, it also means you can have your most important pockets easily accessible without even having to reach for a bag; so, that little pocket on your right shoulder is your healing potions, and that one on your left wrist is your stack of fireball scrolls. That big zipper that runs down your side is your horse pocket. Each pocket is sized and placed on your body by priority and function.

Then on your back you will probably have one big pocket that leads to a giant spread out fishing net... this is your long term storage for stuff you never need to access quickly and don't mind having to telekinetically riffle through to get what your need making it the perfect place to store those 20 nearly worthless goblin spears you hang onto so that you can later sell them to some shop keeper for lunch money.


Magic shelves and retrieving spells

You use magic to create it, so you can use magic to help you order it. After the creation, you can add layers of magic to order everything to your liking. Swords go here, scrolls go there. Every time you put something in, you add a sort of mental picture with it. The moment you think of the wooden staff with a knob on the end, as opposed to the wooden staff with a bulb on the end right next to it, the desired item will fly into easy reach.

Now it's easy! Grab a bottle of stoneskin. Put it knowingly into the bag to get it stored. Next time you think if that particular one, it'll fly towards the hole.

Store obelisks, full plate armour and that nice pebble you like to give your partner. Everything is simply chucked in and retrieved with a thought. Even in a panic you can remember a health potion.


Inside this bag is another bag

The OP mentioned in a comment that there's no problem putting a Bag of Holding inside a Bag of Holding. That opens up the following possibility:

You open up your satchel. Inside is a relatively small and easily accessible shelf, upon which are a neat row of satchels, labeled "scrolls", "tomes", "potions", "stones" and "other." You reach in and take out the satchel labelled "scrolls". Inside that is another shelf containing another neat row of satchels. From that you remove the one labelled "scrolls - A-E", and inside that is a shelf containing the scroll you want. (It is the one that creates bags of holding.)

Of course this approach not only requires a lot of spellcasting to create the bags but also a substantial amount of woodworking, and satchels themselves probably aren't cheap. (Although, since you don't need to carry the inner bags around, they could just be cardboard boxes, if the laws of magic allow that.) So this will be quite a project, but it might be ideal for a very organised young mage with a bit of money and a lot of time on their hands.


Trivial solution. Few ribbons working as conveyor belts. Each ribbon has a different colour in order to classify the type of the items attached to it.

More magical solution, a vortex that keep all the items constantly moving around. The wizard to pick the desired object will have to wait for it to pass within grabbing distance, but the vortex is fast and the wizard has good reflexes.


Your bag is actually two separate bags. The outer bag is what you carry on your belt, and just inside the opening is the gateway to your pocket dimension. The inner bag is significantly larger. The body of the inner bag is in your pocket dimension, but the lip is pulled up through the gateway, folded over the top, and sewn to the outer bag. The inner bag prevents its contents from drifting off, and the inner bag itself can't drift off since it's attached to the outer bag. No additional magic needed, just a good seamstress that doesn't ask a lot of questions.

The fixed size of the inner bag does put a limit on the size of things you can keep in there, but you're already somewhat constrained by the size of the opening. The inner bag can always be enlarged as needed. Your only real limit is the amount of fabric you can find. There's no reason why you can't end up with an inner bag the size of a hot-air balloon.

Objects wandering outside your grasp shouldn't be too much of a problem. Any wizard with sufficient skill to create a pocket dimension must surely have already learned a basic telekinesis spell. An empty dimension would have no significant sources of gravity, so even a gentle nudge will send a wayward object sailing back towards your hand.


An idea is that the portal to the pocket dimension is affected by some kind of luck/fate enchantment. While the outward side of the portal is fixed to the satchel, the inward side can reposition itself to anywhere in the pocket dimension. The luck/fate enchantment acts such that it always repositions to the item the wizard most needs at that moment.

This covers the issue of "To be able to retrieve items quickly". Although it does walk a fine line against "To be able to store items quickly without losing them", since the wizard is at the mercy of fate as to when they can actually retrieve anything that's been stored.

However this somewhat conflicts with "The opening of the pocket dimension is attached to a satchel. You can safely leave things poking through the opening and attach things to the outside of the satchel." Though you could at least make the constraint that the portal can't reposition while something is sticking through it. Obviously then for the bag to remain most useful, one wouldn't want to leave anything sticking through the portal for any great length of time. So it's a compromise.

  • $\begingroup$ If the downvoter could take a moment to explain what they don't like, that would be appreciated. $\endgroup$ Commented Aug 11, 2021 at 18:55

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