Equipment size

For example, halfling/dwarf/children's children's clothing not fitting adult humans or others. Giant's pickaxe being too large to wield by any smaller beings (even large humans). Clothes for a slim person not fitting an obese one. Male chest armor being too constricting for a female due to breasts or female armor being that to males due to the waist. And so forth.

Limitations:
* Character/class limited items, see class-based equipment instead.
* Gender differences in equipment are not part of this.
* Species differences also are not part of this (problem being notably different anatomy rather than size).

Generally not seen in games because it adds an extra layer to track, and is not often wanted by players because it makes some equipment unusable to them that might otherwise be very much wanted (especially true if the game uses item generator and obsoletes equipment).