From the introduction:
Iskloft is a world of brutality. It is a place of violence, literally and figuratively. This is one of the key aspects of the setting and should shine through in every part of it. Each fight should be one that can end in tragedy. Adventurers in Iskloft shouldn’t have 1d4 encounters per long rest, they should fight only when they have to, and pay for every single one.
Beyond that, brutality in Iskloft means there are no shining duels of skilled swordsmen shouting “En Garde!”. Instead, a duel is a fight to the death, where headbutts, tricks and savagery often win the day.
Finally, this brutality manifests in the people themselves. A baby is born with a strange look? Leave it for the wolves. An ally falls and breaks their ankle far from civilization? We can’t carry them. Iskloft is above all a place where players should consider what is pragmatic and profitable, and what will keep them alive.