Far Cry Primal has total of 3 main factions, there are no NPCs in the game that dont belong to a faction, each faction has their own special beliefs as well as characteristics that makes them unique in their own ways
The Wenja[]
Main article: Wenja
Wenja: The main protagonist tribe and allies, The Wenja come from many suns away from a land far from Oros, they come seaking shelter and a home to live in this land booming with life, but they run into evil as the Udam and Izila harm and enslave them, the Wenja scatter across Oros, your mission as Takkar the protagonist is to unite the Wenja and make them strong, the Wenja dont show any significant beliefs but they value the spirits and build totems to mark their territories, they can be identified by their clothing and language easily throughout the game, you will see Wenja people around the map as well as Wenja hunters, the Wenja prefer to use spears and bows and dont have any significant weaponry or elite troops like the other factions.
The Udam[]
Main article: Udam
Udam: These Neanderthal enemies can be found in the northern part of the map. Lead by the powerful fearless Ull They are tough strong warriors that conquer land and eat anything that can feed their hungry population, including humans, they worship the "Stone women" asking her for mercy, the Udam suffer from the cold, their region kills them with what they call the skull fire, its like a flu that causes pain to the head, they have made ways to overcome it by using rot bane as medicine, they also have a powerful weapon that no other faction has, rot bane poison, its a powerful poison that causes anyone who inhales it to get sick and eventually die, those bombs cause enemies to go berserk but we never see it happen on Wenja npcs, just Izila and Udam, They rely on Melee combat and physical strength Like other Far Cry games they have many different variants such as archers with bows/throwing spears, warriors with clubs, chieftains, as well as Scourges, Udam that wield berserk bombs and sling shots. For the archers and Scourges, it is best to stay at range. Use your beast to attack them as well as ranged weapons. While shooting them, try not to stand still as their aim is only accurate when you are not moving. For warriors try to throw shards at them, flank them and hit them in the back or use spears to kill them instantly. Chieftains are powerful enemies with tough armor, so melee combat is not advised. They are rather slow, so keeping your distance is a much better strategy. Use berserk shards, traps, bombs and spears to kill them.
The Izila[]
Main article: Izila
Izila: This tribe of Homo sapiens, found in the southern half of the map, they are fierce and merciless tribe that enslave Wenja and kill Udam, lead by the prideful Batari they worship suxli, the god of the sun, or the sun itself, they do blood sacrifices so that Suxli smiles in their fields, they rely on seeds and agriculture as they have made advancements in growing and harvesting plants to feed themselves, they also use fire, they have successfully managed to make fire bombs, an early version of what can be considered molotov's, but they fear one thing, Krati, Krati betrayed his mother and led a rebellion within the Izila tribe. The rebellion was destroyed, and Batari was forced to burn her own son alive for his crime. All that is left of Krati is his mask that has been placed in his tomb. like the Udam they have many variants, however they are a bit more difficult to deal with. The Izila often utilize fire so always try to have your fire resistance booster on when you want to fight them. Use the same strategies as the Udam variants but be careful of their unique ability to throw fire bombs.They also have better aim and accuracy than the Udam as they rely more on ranged weapons, they also have way more females as soldiers compared to the Udam Their chieftains are particularly powerful and use fire, so it is best to use your berserk shards on them, a couple should be enough to kill them.