The last instance cluster of LotRO’s previous expansion, “In Their Absence,” was rather good. It had interesting and fair puzzle bosses, a boss fight that involved slapping hobbits, and meaningful trash mobs. Fighting trash took you through a progression of enemies to let you get comfortable with your team, to introduce new mechanics gradually, and to explore variations on those mechanics. The first group might have a few normal spiders with a new poison ability, the second with one bigger spider, and so on until you get to the spider boss fight. Another wing has several types of poisonous goblins, introduced one at a time until the fight where you get to navigate all their abilities at once. And so son. The little of the raid that I saw had genuinely difficult trash fights, in which raids would work out how best to deal with this half-dozen enemies and their abilities given the group composition.
Guild Wars uses more of the standard copy-and-paste approach to trash. Until you get to enemies that mirror groups of human players, you have a half-dozen enemies that cover most of each zone or mission. They differ between most missions, but once you’re in, that same group of insects will repeat itself a dozen times. The most extreme example I have seen was vanquishing Zen Daijun in Factions; am I mis-recalling that every single group was an Afflicted Ritualist with two other Afflicted, plus the occasional supplementary monk?
It makes sense that the military patrols have a standardized composition, but so do the bugs, the psychic plants, and the rampaging cattle that inexplicably roam with crested healer-birds. (Maybe that last pair is a rhinoceros cousin and what happens to tickbirds under strong selective pressure.) I suppose I would be here speculating about the wildly inconsistent and randomized setting if there was more diversity in the spawns, or perhaps muttering again about “the same goblin, but this time in blue!” Because players are unsatisfiable jerks.
Later zones tend to get more diversity, because you do not want to overwhelm new players with thirty varieties of monster while they are still learning the buttons. As I said, enemy groups increasingly mirror character classes, and later ones exhibit more variety in appearance. While the different types of humans mostly look alike, at least in the scrum of combat, plants show big differences between the necromantic kirin, overgrown tanks, murmuring healers, or dragon root elementalists. Factions does well on this score (other than the Am Fah and Jade Brotherhood), with strong visual differentiation between Afflicted classes. Nightfall has more human foes and gets less variety until various shades of demon arise. Ooh, glow effects.
The Fissure of Woe is a great example of both variety in trash spawns and the successful use of limited tools to create interesting effects. There is a baseline set of spawns that you will see across the map: shadow foes and demons, with a few skeletal options. They cover the center. In the forest, they transition to various types of aggressive plants. In the swamp, you get hydrae and skales. There are ghosts on the mountain and spiders in the tunnels. One zone, several regions, several enemy compositions. These become more interesting when they interact, either between groups or with multiple groups. Three copies of the same thing can be interesting when you are trying to pull one patrol away from a standing group and another patrol while there are three pop-up spawns in the area. Some tools you do not use against some foes, so when you over-aggro on the border between areas, you must think fast about how to counter several groups’ tricks.
But logical diversity is possible early on. Take the first explorable zone in Factions. Mantids are the baseline creature, covering the plains and the cave/temple. If you approach the water or the edges of the hills, you find kappa. There are tengu in those hills, and there are a few other foes about as well. Unlike later areas, there are few enemies with few skills, with lots of space between them. In this small pond, the per capita variety of enemies feels large and unforced.
There is a tension here. You want a consistent world, but satisfying gameplay demands variety. But you do not want it to feel forced, like the developer was also bored or had a checklist to get through. But sometimes a random bit is fun, so long as it makes sense; toss in some of those plant monsters around a garden that went way too wild or have a hidden enclave like LotRO’s Enedwaith hobbits. You want consistency and variety and fun gameplay and coherent world-building.
Give me enough consistency for me to be able to apply what I already know to this next fight. Give me enough variety to keep things fresh, rather than saying, “not another group of X.” Gameplay always trumps, so feel free to insert something interestingly random as long as it is good rather than your charr quota for this zone. Keep the world coherent by giving some cover story or change in scene when the interestingly random happens.
If only we knew the magical (and highly individually idiosyncratic) formula for “fun” that balances all that. But don’t worry! If the players like your game and are enjoying themselves, they will write their own justifications for why whatever is before them is good. If they do not and are not, no story fig leaf or infinite variety will save you.