Bandits recognize no authority but their own.
Bandit groups typically number between 10-60 combat-trained members (foragers), about three quarters of whom are males. In addition to this number, there are typically another 5-30 women and children that are kept hidden in some variety of fortified camp/lair, where the bandits feel they can safely return on occasion to reacquaint themselves with loved ones and store their gains. They are led by a bandit chief, typically of 4-5th level. Among the foragers, 3-24 will be 1st level; 1-8 will be 2nd; 1-4 will be 3rd. There is then a 25% chance of a sub-chief, who will be 4th level. 10% of bandits will be supported by a single shaman, guru or cleric.
There will be three sorts of encounters with bandits:
- Scouting party. 3-12 members are encountered on their return from a reconnaissance or a raid. There's a chance that the party will surprise this number, that some of them will be wounded and that they may be carrying anywhere from 250-1000 g.p. from the treasure they took (if this was a raid). A reconnaissance party will have been scouting a target; if the party chooses to parley, there's a small chance - if the party looks the right sort - that the bandits may ask the party to join in with them on a raid. They'll be moving during the day, camping at night.
- Encampment. 5-40 members will be camped, possibly waiting for raiders or a reconnaissance party to return, potentially celebrating before returning to their lair, more likely sustaining themselves with fishing, foraging, cutting trees, drying hides or other task necessary to sustain the whole bandit group. The season should matter; in fall and winter, the encampment will almost certainly be focused on supplies; in spring, reconnoitering; and in summer, raiding. There's a chance the party may surprise them. If the party chooses to parley, several of the bandits will slip out of the camp while the leaders talk, until a chance comes to feather the party with arrows while the encampment attacks and kills the players. Note that a bandit encampment, from the outside, will not look different from a working crew, except to a thief (who should roll a d12 - a number equal to or less than their level will reveal the truth).
- Ambush. The whole bandit group (10-60) will have decided that the party is worth raiding, or else they will be raiding a village, manor, caravan or some such the party has entered or associated themselves with.
Bandit camps are fervently sought after by authorities. Successful bandits who accumulate enough wealth will sometimes 'retire,' buying their way into the establishment, sometimes obtaining a pardon by bribes or through committing their men to an authorities' cause in times of war.
Bandits will have unusual knowledge of a given hinterland, making them invaluable as spies or smugglers. They prefer mounts in open country but will not use them at all in mountainous or forested regions.