Hammerspace is a fictional concept; an extra-dimensional storage area that's accessible when needed. It's used to jokingly explain how characters in animation, comics and games (Japanese ones in particular) are capable of producing objects seemingly out of thin air.

The area draws its name from a semi-common cliché in humorous anime and manga: Male character X offends or otherwise angers female character Y. Y then draws a wooden mallet, ranging in size from large to downright ludicrous, out of nowhere and bashes X with it. Hammering is purely for comic relief, incapable of advancing the plot or causing permanent damage. The term was largely made famous within the Ranma 1/2 fandom. It does have parallels in western animation, especially in Warner Brothers cartoons where a character could pull almost anything from behind their back or literal nonexistent pocket for a gag.

Despite having its roots in other fields of entertainment, Hammerspace sees use in explaining the peculiarities of video games, particularly console role-playing ones; why doesn't a character wielding a sword half his size appear to be carrying one until he actually enters combat?

Not much of the nature of Hammerspace is known, except that it should contain blunt objects in vast amounts. The laws of physics in Hammerspace are fairly peculiar, as is the nature of the link between the area and its users. This can be observed in – for example – the way many Final Fantasy heroes are able to carry 99 Potions and 99 Hi-Potions with no trouble, but have no room to carry 100 Potions no matter how many other items they have.

In Japanese anime, Hammerspace may owe its existance to the fact that the traditional samurai carried their katana swords in sheaths on their backs rather than at their waists, as was more common in the rest of the world; therefore Japanese would find it less odd if someone reached over his shoulder and produced a weapon.

In RPGs, the humorous mythical item used for this near infinite space is sometimes called a magic satchel.

See also

• Cartoon physics