Fable 2 added a layer of semi-simulation to the RPG gameplay, and while it had its shortcomings, it was an interesting attempt to widen the gameplay in the single player RPG. MMOs require more than this in the next-generation of games, I believe. They need a realistic simulation model. That doesn’t mean they need to react just like the real world (we can have magic, etc), but like movie logic, the games need to obey their own “laws”.
Some MMOs have recently added the idea of nocturnal creatures. A good example would be the Trolls in Lord of the Rings Online, which can only appear at night, because according to Tolkien, they turn to stone during daylight. Aion will also have some mobs that only come out during the day or night. This is a step in the right direction, but the implementation in MMOs so far has been piecemeal.
Wild animals should react as wild animals react. Deer, for example, do not stand around while a person walks past, nor do they attack, unless all other options have been exhausted. Except in LOTRO, where they do the deer equivalent of “Bring it on.” They should run away and require you to bring them down with ranged attack if you want their hides. Likewise, I’ve wandered through a wood in the middle of winter and come across bears wandering around – have developers never heard of hibernation? I’ve wandered through swamps in the middle of torrential rain, and seen insects flying around by the dozen – insects don’t fly in the rain, for goodness sake. The point is this – if you are going to implement a set of weather effects, then they should have world implications, just as the do in the real world. Otherwise, the rain or snow is just a visual filter and we might as well dispense with it.
Now this might sound like pedantry, but I believe there is more to it than that. By ensuring that the MMO world is governed by rules that make sense, you create a world the player can believe in more, and offer more gameplay ideas. In today’s MMOs you could wander past a set of trolls living in the same patch as a set of giant swamp insects. There’s no competition for resource going on there between them as there would be in real life: the two species would compete for land and food sources.
Now, if a next-gen MMO were to implement this level of simulation, then you could have boundaries where two species would compete, and if the player were to tip the balance, by coming through and killing say 30% of one species, then the other species would have an advantage and start to take over their enemy’s land, reproducing to increase their numbers (let’s get rid of spawns this way while we’re at it; we’ll have hatchlings, young and then adult morphing, thanks). The simulation could then reset the numbers by some sort of natural disaster (disease, earthquake – I don’t know; I’m making this up as I go along) so that mobs were available for quests kills, but this way we would have a natural ebb and flow of mobs in a living world. A living world: imagine how that would feel to play in – better than running around the cardboard cutout worlds we have today, wouldn’t it?