Passive NPCs would simlpy be a kind of NPC That wanders around larger scale builds and cities, players can even flip a switch in their “Beacon” to allow passive NPCs to spawn, giving them the ability to fill their town with people to give it a slightly more homey appeal rather than a desolate, empty, ghost town.
Villagers: When they spawn, Villagers will begin working on minor tasks such as farming, cattle ranching, and resource collecting. Villagers will only venture out into the regenerating portion of the world to gather wood, animal meats/skins, and other minor assorted materials. However, to keep things balanced, NPCs gather at a FAR Slower rate than players, giving them a slightly more realistic gather time. While they are out, they can encounter enemy NPCs and battle them. You can choose to assist a villager who might even reward you for your courage by giving you some money or resources for free. Or in some rarer cases, perhaps you assist an adventuring NPC Who does not farm or gather materials, but instead seeks a more exciting life and offers to assist you in your adventures, even possibly running errands for you, otherwise remaining within the confines of one of your beacons in a passive manner until you need him/her again later.
When passive villagers return to the town and enter a city beacon, they then turn into merchants, selling their goods to other players and other NPCs. The reasons they might sell to other NPCs is so other NPCs can stay in town to secure a far more passive life such as baking or tailoring.
NPCs would life in whatever housing the land owner/beacon placer has created within their beacon. Perhaps, there could even be a system to select an NPC or a small group of NPCs, “lead” them to a house, then deselect them. This will set their “Home” so you can keep some houses empty for the uses of visiting Players.
Other passive NPCs: Dogs, cats… Well… Uh… Oort’s world’s equivalent of Dogs and cats… would favor beacons as well, in storyily picking up scraps and digging out of the garbage cans to survive, these are rarer, but can be trained as companions. Perhaps even flying npcs in this category as well?
In some cases as well, an NPC might be able to be paid to deliver a message to another city, or player. The idea of a mailbox was not long ago mentioned, but I think this is a great opportunity to create risk for message systems. A delivery NPC might be attacked and killed on his way, dropping the letter for anyone to find! OH MY!
Other passive NPCs might not have any super purpose, and might wander from town to town, favoring paths, if any [Player placed cobble paths for instance].
Guards and robbers: In some cases a villager might not choose the super passive life, this means it might be necessary for guards to wander town and patrol paths near the city boarders. Sometimes a bandit might be lurking around the woods, or along a path! Guards and bandit guilds might engage in small area battles with one another! Help the guards to maximize your favor with the town villagers, or to receive minor gifts, or help the bandits to minimize/get rid of risk of being attacked! Perhaps they will toss you a small payment for your assistance before departing after the battle?
I just felt it was necessary to put up a post that includes passive NPCs as well to help increase the feeling of this being a living, dynamic world, rather then an empty/barren one.