Trolls are simple-minded beasts that wander out of Trollskóg to plague humans. Their primitive nature is easily fooled by even the simplest nitwit. The many varieties of trolls are found across all of The Five Worlds. Many supernatural creatures go by different names, but they fall under the troll species. This is based on observed behaviors. Trolls are stupid, and rarely manage to use tools. They have a certain lack of body control and often stumble, drop things or even punch themselves. They live in solidarity or in groups of less than half a dozen. Within groups they are often violent and have little to no skills of diplomacy or etiquette. Another commonality among trolls is that they are weak against the purity of man and iron. They burn at the touch of iron, and they can even smell men of The Iron Faith. Most recorded encounters mention that trolls die evne just from one strike by an iron sword or axe. Trolls vary based on terrain: Forest trolls, lake trolls, mountain trolls, river trolls, rock trolls, mud trolls are some that are mentioned in stories and tales, but they go under other names, such as the nokk, which is a pond troll. The trolls' simple-minded nature does not equate to them being harmless. On the contrary, these beasts are ferocious and vile creatures that anger when confused. They are also fierce predators that bait humans to eat them.
Trolls come in various shapes and sizes, but they are generally taller than 3 meters (10 ft.) and often broad built and very strong. Even though trolls have various appearances, they all look natural and camouflaged. Their skin could be made of rocks, have a beard of moss or trees could grow from their backs. If they stand completely still, it could be very hard to find them.
Perception and Sensory Capabilities
Trolls often have bad eye sight, but a keen sense of smell, especially towards the smell of people with The Iron Faith.
From Creatures of Trollskóg, volume I
By Lidvar Brodvarson and Irv Irváson