Monster-infested wilderness can be considered pacified if threats are systematically sought and either destroyed or driven off. Pacification is a relative property measured by the chance of encountering a hostile foe. A typical wilderness offers a 1 in 6 chance of an encounter after 4 hours of exploration. Greater infestations might generate 1 in 4, 1 in 2 or even more often. Towards pacification, areas may decline to 1 in 8, 1 in 10 and below that might be considered completely pacified.
In order to pacify an area, a party of explorers must methodically search out a 1-mile area for any notable features and hostile encounters. A group might cover a 1-mile area of clear terrain, such as grassland or desert in 4 hours. Rough terrain requires twice as much time. One pass of the area will reveal any significant landmarks but may not find any monsters lurking there. Continued searching must be conducted to flush them out.
After an encounter resolves with the enemies defeated, make a check of encounter chance. Unless an encounter is indicated, reduce the chance of encounter by one die size. For example, after a fight in a 1 in 6 area, a 3 is rolled on D6. The area moves to 1 in 8. After another 4 hours of searching, another encounter resolves. A new check produces a 1 on a D8. The area remains at 1 in 8. Areas only go up in danger very slowly, if at all.