Spinks was pondering NPCs in a rather fine post, and I’ve been quite firmly hooked by Fallout: New Vegas, a game with an awful lot of NPCs by necessity, being single player. I think it uses a combination of approaches that Spinks outlines; for the most part, for computational sanity, NPCs only exist when you’re around, a slightly solipsistic approach, though not quite as extreme as something like Saints Row 2 where things can stop existing if you stop looking at them. Some NPCs do persist, though, such as trading caravans that you’ll sometimes find at a particular outpost, or sometimes you bump into in the wilderness as they’re on the move.
The life of most Fallout NPCs isn’t wildly exciting, they generally wake up at a certain time, make their way to their shop/office/patrol area, sit at a desk or wander in circles for a bit, then go back to bed at the end of the shift. Fallout can get away with this as a single player game for a couple of reasons: you always have an option to wait for up to 24 hours, if you need to rapidly skip to a particular time of day, and NPCs are incredibly tolerant. Stroll up to a sleeping questgiver or shopkeeper, vigorously poke them until they wake up and you’d expect them to blearily peer at a clock and scream “What the hell are you doing in my house at three in the morning?”, or at least mumble “blargle glargle NO, ROY HATTERSLEY, GET AWAY FROM ME WITH THAT TIN OF KUMQUATS”, but they just stand up, nice and calm, and present exactly the same dialogue options as if you’d walked into their shop, a game/world compromise I can more than live with.
Even a few straightforward rules make the game world seem more like something that exists in itself rather than being an amusement laid on entirely for your benefit; a caravan of a trader with a couple of mercenary bodyguards follows a preset path, some bandits wander around a certain area, if the two bump into each other they fight. If you’re close enough you hear the gunshots, and you can either steer clear or go and investigate, help one side or the other, and most importantly sprint over to any corpse before it’s cold and strip it of weapons and armour. As the number of elements and interactions increase so you start to get hints of emergence; this can be a positive and interesting thing, like the Dwarf-eating carp of Dwarf Fortress, but when the game isn’t entirely glitch-free to start with it can exacerbate problems.
Near the start of the game I got on the wrong side of one of the big factions, and not long after I was wandering through the wilderness when four friendly (or at least neutral) markers appeared on the HUD compass heading right for me. It turned out to be a group of assassins, but terribly sporting assassins. I guess “being mown down in a hail of high-velocity rifle bullets fired by assassins half a mile away you had no chance of detecting” scored badly in focus group questionnaires, so instead the group approach and have a little chat; “Good morning sir, my name’s Geoff Assassin; assassin by name, assassin by nature as I always like to say, don’t I lads, ha ha ha. Now, our leader is a little bit miffed, so I’m afraid we’re going to have to assassinate you. Sorry about that. En garde!” I wouldn’t be surprised if I found a card when I returned to my rented room: “Sorry we missed you! A representative called around to assassinate you, but you weren’t in. We’ll try again tomorrow, or if you’d like to be assassinated earlier please call in to our depot between 9am and 5pm.” After the initial pleasantries they’re annoyingly hard to kill, but a couple of frag grenades proved most helpful and I resumed my wandering. They’re persistent blighters, though, and every few (in-game) days another group appear making a beeline for your character. I say “making a beeline”; they can interact with (i.e. shoot) things like hostile wildlife, traders or patrols from other factions if they encounter them on the way, and they’re a lot easier to deal with if you can shoot them in the back of the head while they’re distracted by something else. Sometimes, though, the rules go a little wrong; I’m not sure if they get stuck in a combat state with something else, or have pathing issues, or just forget exactly what they were supposed to be doing, but occasionally I’ll find a group of confused assassins milling around a small rock formation, completely ignoring me as I wander past.
Perhaps, though, that just makes the NPCs a little more human after all. I mean, were it an MMO, such actions wouldn’t be beyond the realms of possibility for player characters; “The behaviour of the Legionary Assassin Squad in the field was erratic at best…“