Omegaverse (also known as a knottingverse or A/B/O verses) is an alternate universe that originated within the m/m erotic fanfiction space. In this universe, people have defined roles or 'dynamics' called Alpha, Beta, and Omega.

Aside from having specific sexual characteristics, Alphas tend to be big and dominant, while Omegas are small and have submissive tendencies. Betas are usually very similar to humans, without the defining characteristics of either Alpha and Omega, but each author chooses how to define them in their world.

The initial concept of Omegaverse was to explore the idea of males (Omegas) who experience pregnancy, called male pregnancy or m-preg, with a male partner (Alpha). The ’verse quickly expanded to f/f, m/f, and multiple partners, but the concept remained that it’s the Omega who experiences pregnancy while the Alpha is the one who impregnates.

How these dynamics behave, particularly the erotic interaction between Alpha and Omega, is what makes a story omegaverse. Common tropes include:

• Irresistible sexual attraction and compulsive sex through biological imperative (between Alpha and Omega)
• Power imbalance
• Omegas being disadvantaged, rare, or sought after in the social hierarchy
• Knotting - when the base of the Alpha’s penis swells and locks them securely with the Omega so sperm doesn't escape
• Pregnancy
• Bonding (with claiming bites, true mates, etc, like in shifter PNR)
• Heats and ruts

These Omegaverse-specific tropes can be paired with any setting, fantasy being, and trope. However, Omegaverse is most popular in Romance and it has developed in sub-genres such as dark romance, sci-fi romance, PNR, monster romance, and contemporary.

Each author's Omegaverse will be slightly different and they will add their own rules for their versions. I love epic fantasy and dark romance, so all my omegaverse stories are dark romances based in epic fantasy settings. However, there are tons of great Omegaverse stories on fanfiction sites like AO3 and it has exploded on book retailers in recent years.

To find out more, check out: Fanlore: Alpha/Beta/Omega