Ratskins

Ratskins are only mentioned in the fluff of Necromunda and are never seen, it's actually the bad ones who get any screen time. That's because otherwise there would be a swathe of neo-buddhist/pacifist armies organising an exodus from the tabletop each battle, which doesn't really work in the setting, because 40k is grimdark like that.

Unfortunately, "Ratskin" is a pun on "Red Skin", which is not politically correct, especially since their fluff reinforces old stereotypes. The term also describes the traditional get-up of an under-tribal, who wears rat-skins for clothing.

For their own part, the Ratskins call themselves the "Kuloq" which means "The People" and that their origin story was that their deity "Ku" got lonely at having no-one to share his planet with, and so: "in an act of grief and longing he laid himself down upon the planet and allowed his essence to seep into the soil" and that the people are the descendants of his left hand... I think that's enough said about that.

Ratskin Tribes

Unlike the raving bands of Scavvies who share the lower territories of the hive, the ratskins are NOT characterised by mutation, cannibalism or violence. They are probably the closest thing to right-thinking upstanding citizens that you'll EVER hear about in the year 40,000 that aren't brainwashed by Tau propaganda.

They do not interact or trade with the hivers in any way, finding their customs and behaviours bizarre and strange. "Normal" Ratskin tribes do not engage in violent conduct, arguing that the soul of a slain enemy will return to seek vengeance, thus if they ever encounter "normal" citizens the Imperium they will get the FUCK out of dodge. You might never see them but they were there. Some Ratskin tribes do engage in violent conduct, but they are a minority and were added as optional extra rules to differentiate between different Ratskin tribes.

Away from the Preachers of the Ecclesiarchy, the ratskins do not share any of the same beliefs common amongst the normal citizens of the Imperium, instead they have formed an animistic form of shamanism in relation to the hive. Coming to worship the spirits of the hive they treat the city as a living ecosystem prone to moods and tempers.

The hive guilds have placed bounties upon the ratskins, and they are not welcome amongst imperial society, mostly because this hippy crap offend's the Emperor.

Though they live primitive, self-sufficient lives the Ratskins do consider Archaeotech to be sacred and while they do not use ancient technology, they maintain that sites containing archeotech are favoured by the spirits. Thus locations containing archaotech are often the only static territories held by the nomadic ratskins.

Eventually, Fanatic Magazine eventually settled down and wrote out what makes different Ratskin tribes distinct from each other, which gave them rules benefits

Ratskin Renegades / Badskins

Aside from the peace-loving, nature-worshipping angle, Ratskins are also depicted as gambling, drinking, whoring good-for-nothings who mosey into the saloon and get evil looks from the inbred backward locals.

Those ratskin tribesmen who come into contact with the hivers are shunned, as they are considered to be "tainted by civilization". These "Badskins" often become vagrants and troublemakers, though some do find legitimate work and can be hired by gangs in the tabletop game to serve as scouts, guides or trappers.

Occasionally drift together to form groups of "Ratskin Renegades", becoming violent and looting and stripping hive territories dry before moving onwards.

These ratskin renegade tribes are organised much like normal ratskin tribes, led by a Chief who is elected from amongst the warriors in the tribe, accompanied by the warriors and unexperienced braves armed with whatever they can loot or purchase from black-market dealers.

In a nutshell this means you get to use Ratskins Renegades as a playable faction in Necromunda.

Totem Warriors

The Totem Warriors are those amongst the ratskin renegades who seek to purify themselves in the sight of the hive spirits. For this they are revered by the badskins as well as the more peaceful ratskin peoples. They are seen as wandering warrior-pilgrims who spend their time on quests or in prayer-trances to the spirits of the hive.

In their devotion to the spirits, the totem warriors believe that by slaying an opponent in close combat, they can absorb their enemy's soul, thereby avoiding the spiritual vengeance of their opponents as well as adding to their own power.

While Totem Warriors eschew ranged combat in all cases, their purification rituals and superstitions do invest themselves in their melee weaponry. When in the hands of the totem warriors they can inflict damage far beyond that of their normal type. To the people, the totem Weapons are infused with the power of "spirits of the hive" (sounds like how Space Wolves view their psychic powers),

Ratskin Savages

There is an another travelling warrior amongst the Ratskin tribes, the Savage. Though unlike the Totem Warrior they normally do not remain attached to gangs and only join in after receiving their hired gun fee and then leave after a short period.

This is fine because Savages can start with much higher statlines than Totem warriors (who progress in XP along with the rest of the gang). So they make for a good method of quickly buffing your force if you need an extra pair of hands.

What also distinguishes the Savage from the Totem Warrior is how they behave. The Savages are NOT seen as holy wanderers, rather they are seen as the absolute worst of the Badskins, who not only have been "tainted by civilisation" but want to see all of the hive dwellers get slaughtered and falls into unstoppable rages in order to get this done. In rules terms they focus entirely on close combat, and gain the two-weapon bonus even if disarmed, they also cannot be parried in close combat on a 4+ due to the sheer ferocity of their attacks.

Finally, if they take an opponent out of action (models don't usually die straight away in Necromunda) then the Savage can descend on them and attempt to give them a rusty-bladed scalping if they can't get away in time, which will basically give the opponent's character some form of disfigurement (and a permanent penalty like being blinded or deafened... or DEAD).