In Civilization VI, a unique unit is a special unit that is only available to a specific civilization. Some leaders also have unique abilities that give them access to unique units once they discover the appropriate technology or civic. Unique units do not require resources (prior to Gathering Storm) and have special attributes that make them superior to standard units.
Note that, unlike in Civilization V, unique units do not always replace standard units. When they don't, they often fill a niche for each player that no other civilization/leader can fill at the time, giving that player a distinct advantage over his or her rivals. However, these standalone unique units also cannot be pre-built and upgraded into, so they require more Production investment. Note also that unique units may belong to different eras than those they replace, which is important when considering era-specific Policies or the effects of Great Generals and Admirals.
There are rare instances in which a unique unit of one civilization can be controlled by another one:
- Genghis Khan has a chance to capture unique cavalry units when he defeats them with his own cavalry units.
- The Sea Dog can capture unique naval units when it defeats one.
- A civilization that levies the army of a city-state can upgrade its levied units into their unique units. These unique units retain their unique identity when the city-state regains control of them, and can be levied by another civilization that becomes the Suzerain of that city-state.
- In Heroes & Legends, Hunahpu & Xbalanque can resurrect defeated unique units to fight under new leadership.
Despite all of these instances, there is currently no special ability or method that can be employed for a civilization to build another civilization's unique unit from scratch.