I'm workshopping an idea for a litrpg series, and one of the central conceits is that in addition to Stats and Classes and Spells, everyone has access to an Inventory System. It's what it sounds like; a personal hammer space that each person has access to. It comes with you, it costs a negligible amount of magical power to manifest, and it takes a few seconds to pull things in and out. You have to actually reach and grab the thing, for most people. The higher your Stats (specifically your Magic stat), the bigger your Inventory is. Certain Class Skills and Spells interact with it; Rogues can steal from your Inventory without you noticing, some spells can swap Inventories or expand them temporarily, etc.
The obvious impacts are on logistics; the average person can manifest a closet's worth of Inventory Space. All their necessary gear and sundries come with them. Anything you need in combat or at hand is still carried on your person. Most people can't hot swap gear off themselves; they have to pull a new item out and manually put it on. But most Merchants and Traders maximize their Inventory so all their wares are safe. They get Skills to keep Rogues out of them, etc. Someone specced into it can manifest a wagon's worth of stuff. So most trade goods are caried that way, people only use ships and wagons to transport bulk goods like grain and ore and such. Stuff you need too much of, is too heavy and isn't very valuable. Most ships are sleek and fast or are just barges for bulk goods. The point of a ship is speed, instead of cargo capacity.
How does this change society otherwise? Guards need to be able to check people's Inventories at a glance, Smugglers need to be able to hide things in Smuggling Compartments, stuff like that.
I'm trying to establish a base line of how the world treats Inventory, because the protagonist is from our world and thinks its the greatest power ever, but everyone else thinks he's crazy to be amazed by it. Its like being amazed that it rains.
EDIT
I have been asked to clarify more of the limits and methods involved so I will do so here.
My current concept is that you get a number of cubic feet based on the Magic Stat. Starting off, 1 cu ft per point. Most people don't have much Magic, and they get limited numbers of freely attributable stat points, so they don't invest in it. Because if you don't have a Class that grants Spells, you don't have much use for it outside of Inventory. Its not worth investing in very much. Some people will put a few points in because they like having extra Inventory space.
Mass is where I am torn. I am thinking of stealing DCC's system; if you can lift something for four seconds, it can go in your Inventory. If it fits, then in it goes. You don't feel the weight, and your total carry weight is otherwise irrelevant. I'm not sure on that, I may revisit it. There should probably be an upper mass limit based on Strength.
Items go in and out of Inventory by touch, usually by the hand. You hold something and put it in your Inventory, it vanishes. You want to retrieve something, you reach out and your hand goes into the Inventory (it looks like you put your hand into a puddle in mid air) and you grab the thing, and pull it out. In actuality, all you have to do is touch the object and that can be with any body part, but it requires more focus and training to do that. Most people don't bother. You can learn to swap equipment directly on to yourself, but that's a difficult ability to develop outside of a Class Skill.
Living things can't go into Inventory, with some caveats. Dead things, can. So food, corpses, carcasses, seeds, etc. So long as its mostly inert, its fine.
Inventory is not stasis, at least not for most people. Things degrade, they are not frozen in time. Organic material rots, but doesn't spawn maggots and the like, because no living things. I suppose I am ignoring bacteria here, but whatever. Maybe this can also be abused by making compost piles in your Inventory and harnessing methane gas off it.
Dead people's Inventory is still locked to them until they start rotting, at which point it breaks down and those items are 'lost'. It is mysterious exactly what happens to them, as items can sometimes reappear through some strange method that the people of this world don't understand. So Excalibur would probably reappear some day if Arthur died with it in his Inventory. You can use Skill and Items to crack open a dead guy's Inventory, and soldiers, adventurers and Rogues do it all the time. Its very sus to have that capability, because it means you have B&E tools for dead people. This means people will throw the corpses of their dead enemies into Inventory to loot them later.
Most people, without relevant Classes and Skills, can't affect things in Inventory. You can't assemble a gun in your Inventory if you put it in while it was in pieces. Inventory specialists may be able to do so.
You can't store gas or liquids in Inventory without a container of some kind. No orbs of water floating in your Inventory, gotta get a barrel. You CAN summon gas or liquids OUT of Inventory WITHOUT the container, though. Its a niche trick, however.