Practical knowledge of the outdoors, and the ability to live off the land. The knowledge of plants and animals.
Initial Level Starting Outdoorsman skill is equal to(2% x Intelligence plus Endurance). Average characters will have a 20% skill. (Fallout 2.) During the game you could find scout handbooks. These are skillbooks that can increase your outdoorsman skill by 1-5 points every time you read one.
Purpose: The Outdoorsman skill's job is to decrease the likelihood of bad random encounters with the possibility of increasing the odds of special encounters. In Fallout 2, a succesful outdoorsman check will give you the choice of whether or not to have an encounter at all. This does not apply for special encounters however. You are forced to enter the scene.
Though you are granted the ability to raise the Outdoorsman to 200%, or 300% for Fallout 2, the real cap would be around 100%. Raising it to ridiculous levels will have no effect, and will bring waste to your skill points.