Hierarchy
Also: hierarchical polyamory, descriptive hierarchy, prescriptive hierarchy
Any structure that formally ranks relationships, typically into primary and secondary. A key distinction is descriptive hierarchy (naming how life is actually entangled) versus prescriptive hierarchy (rules that cap how much a relationship is allowed to grow).
Hierarchy in polyamory means relationships are ranked, usually with a 'primary' partner who has more entanglement, priority, or decision-making power, and 'secondary' or other partners below them. Hierarchy is one of the major dividing lines in polyamory: some people find it honest and practical, others reject it in favour of non-hierarchical or egalitarian models.
The most useful distinction the community draws is descriptive versus prescriptive. A descriptive hierarchy simply acknowledges real entanglement — you share a home, finances, and children with one partner, so that relationship unavoidably carries more logistical weight. A prescriptive hierarchy goes further, imposing rules that cap what other relationships are permitted to become: this partner can never stay over, can never be told 'I love you,' can be vetoed at will. Critics argue prescriptive hierarchy is where couple privilege does its damage, because it denies outside partners the chance to grow into full participants.
Many experienced polyamorists land on accepting descriptive hierarchy as an honest fact of finite time and shared life, while being wary of prescriptive rules that treat people as permanently capped. Others build genuinely non-hierarchical lives. There's no consensus that hierarchy is wrong — only a strong consensus that outside partners deserve to know the terms up front.