Generally regarded as an umbrella term that includes polyamory, open relationships, swinging, solo poly, relationship anarchy, and poly-fi relationships. The use of the term is like how queer is the umbrella term that covers gay, lesbian, bisexual, pansexual, etc.

Sometimes it is called “consensual” or “responsible” non-monogamy.

Relationships where the participants are free to take new partners.
Typically, solely sexual (not emotional friends with benefits.)

More casual additional partners outside an established, primary relationship.

Hundred Mile Rule: is an agreement permitting sexual liaisons with people outside a partnership or marriage if they take place far from home. Some married long-haul truckers and military service personnel, for instance, have rules that say it’s ok to have sex with other people while you’re out on the road or on deployment.

Practice of having multiple spouses.
More gender normative and heterosexual normative.
Usually tied to religion.

Form of open relationship/social sex activity in which partners in a committed relationship engage in sexual activities with others at the same time.

Swingers who engage in casual sex maintain that sex among swingers is often franker and more deliberate which they interpret as more honest than infidelity.

Parties and clubs are attended with the main couple who introduce other people into their sexual act or perform with their main partner present.

*This type of situation is not considered an open relationship by the partners and outside romantic relationships are generally not considered acceptable.

Multiple romantic relationships at the same time with knowledge and consent of everyone involved.

People in ploy relationships tend to view their relationships equally rather than assign labels like “primary” and “secondary”. BUT NOT ALWAYS.

These relationships may or may not include sex. These relationships are not defined by sex but are interested in pursuing multiple loving relationships.