Hammerspace

Hammerspace is a not-so-theoretical pocket dimension wherein large weapons may be stored until needed. In the PPC, these include Hammerspace knives and Agent Kayleigh's mace, for example.

The term originates from a popular anime trope in which characters (almost always female ones) are able to produce ridiculously-sized mallets from seemingly nowhere on command, usually in response to lechery.

There are several items that produce hammerspace, such as portable holes or a bags of holding. Because Tardis are larger on the inside than on the outside, they may be said to have a hammerspace-like quality. Some magic-users are also able to conjure objects from seemingly nowhere, which replicates the hammerspace effect. Additionally, some video game characters are accepted to have hammerspace somehow due to the massive inventory they store yet have no pockets or bags to heft.

It is frowned upon for Agents to have access hammerspace as a superpower if they are not from a hammerspace-enabling canon (except in circumstances in which it would be really funny), but any agent may hold and use an object that is hammerspace-enabled without any training or background. In fact, bags of holding may be more convienent than regular luggage if an agent can get their hands on them.

Characters who are not canonically supposed to have Hammerspace occasionally develop it because of an author forgetting to mention the presence of an object before it is used. If the object could reasonably be kept within a pocket or be found in the surrounding area, this is not a problem, but the sudden appearance of a large object from nowhere for no apparent reason is a charge. For example, even though Murdoc Niccals is a cartoon character, he does not canonically have the ability to produce shotguns from nowhere, a fact which did not escape the MSTers of Like it or not, in which he inexplicably did so. Nor should characters in the Redwall or Twilight continua be able to pluck their weaponry from thin air, as Zain did with his scythe and Tiana did with her "samurai sword".

Unjustified hammerspace is very common among Mary Sues, mostly because many of them do not focus on actually being able to carry around everything they may mention as being on their person.