Owls of Minerva (Civ6) The Owls of Minerva are puppeteers who mastermind plots behind the scenes and use espionage to achieve their goals. Joining their ranks gives access to the Gilded Vault, a new building with all the benefits of a Bank, but also grants Gold adjacency bonus as a Culture adjacency bonus as well. It also grants an additional trade route for cities with a Harbor.
Hermetic Order (Civ6) The Hermetic Order values alchemy and occult science above all else. Their success comes from theories and inventions that other societies dismiss as mere fairy tales, such as Ley Lines. Ley Lines are a new map resource only Hermetic Order members can see, which gives standard adjacency bonuses to all specialty districts. They also grant bonus yields whenever a Great Person is earned. Members of the society can build the Alchemical Society, a University replacement building that has all of the base University effects, plus extra Great Merchant points, Great Engineer points, increased Production, and Gold.
Voidsingers (Civ6) The Voidsingers follow a dark religion of ancient gods and sow chaos to control adversaries. Joining them unlocks the Old God Obelisk, which replaces the Monument. It has all of the Monument's base effects, and provides additional Faith and Great Works slots. The Voidsingers also have a unique unit, the Cultist. Purchased with Faith, Cultists can spend a charge to recruit followers in enemy cities, reducing the target city's Loyalty by calling its citizens to madness.
Sanguine Pact (Civ6) The Sanguine Pact is a militaristic regime known for sapping enemies of their will to fight, shunning the sunlight. Joining the pact unlocks the unique Vampire unit, which gains Combat Strength when adjacent units perish. Instead of dying, Vampires retreat to safety with one HP and can be healed back to full by pillaging. Vampire Castles can be placed in any empty tile in your territory or in neutral territory and grant defensive bonuses and extra yields. In later eras, Vampire Castles allow you to teleport units between them