In Civilization 6, barbarians are a pretty simple obstacle to understand: kill or be killed.
In the game's next update, the barbarians are getting a complete overhaul that makes them more than just empty-headed gold pinatas. In the video below, developer Firaxis goes into detail on how it all works.
The February update, set for 25th February and free for all players, adds the new Barbarian Clans game mode. This completely changes how barbarians work in the game, adding six barbarian clans that can be found living on or near different map conditions, and each specialising in a different type of unit. You'll find the camps of the Hills Clan near hills, for example, and the Rover Clan near horses resources.