A Steris (plural steri) was a family unit within the Adnerem species of the planet Adner in the Expansion Region. An steris consisted of between five and a hundred individuals, with the typical steris having sixty four adult members whom would all share a Steri-house together. The members of the house, known as its sterisi, would share maintenance and offer chores around the building between themselves or hire a less powerful steris to preform them. Adnerem culture revolved entirely around steri, with an Adnerems status in society being judged entirely upon the status of their steris and their power within it. Members of a steris who became particularly close sometimes formed what was known as a sterika, a non-sexual relationship in which they became so close they came to think of themselves as a single entity. Steris would occasionally fight against one another in small scale conflicts called raid-wars, in an attempt to alter the status of the opposing steris. These conflicts would never aim to annihilate the enemy but simply defeat them and weaken them, as a weakened steris could serve as a potential future ally.