Resource unit

From Encyclopedia Hiigara

A resource unit (more commonly referred to as an RU) is a measurement of wealth found throughout the Homeworld universe, both the games upon which the setting is based and the surrounding fan media. Originally a gameplay element serving the same purpose as gold or food might in another real-time strategy game (that is, the unit of resources needed to construct your force) it has since come to be a semi-canonical element of the franchise.

What precisely an RU is a measurement of isn't exactly known. While resource units are acquired through the mining of asteroids, processing of crystals, and collection of space dust this doesn't help much as each of these is a fairly general term. Asteroids can be composed of various different materials from carbon compounds to heavy metals. Crystals are just as diverse in materials as anything that forms in a crystalline manner is technically a crystal ranging from silicon-based quartz to carbon-based diamonds and more. Space dust is just as broad a category. In the end, what RUs are a measurement of is largely based on what one chooses to believe the ships that they are built out of are made of.

It is also unclear if RUs are a unit of currency or simply a measurement of mineral wealth. Most fan media points to the latter although a few works choose to believe the former. In the cases where RUs aren't the main form of curency they are nonetheless used in some cases as though they were a currency. This is actually supported by canonical sources. For instance, the Bentusi Exchange, in both Homeworld and the backstory for Homeworld: Cataclysm, exchanged technology and other services for mined resources. In this case RUs could be considered an example of commodity money, like gold was in many eras of Earth's history.