I want my players to have varied encounters. That involves pitting them against all sorts of monsters. The roads attract all manner of adversaries intent on waylaying travelers (or looking for a meal). The forests conceal communities of humanoids and monsters alike. Secluded lairs are home to the most fearsome beasts. But where do they all come from?

Conventional Thinking

The obvious answer is that they are the offspring of others of their own kind. To have offspring, you must (at least in most instances) have a mated pair. This pair must have once been individuals that were in close enough proximity to find each other in order to mate. That implies that there must have been quite a few individuals in relatively close proximity to each other in order for the species to survive.

Each creature may live individually, within a family unit, or within a community. Though, no matter how they live, there must be others of their kind around somewhere. The amount of food each individual requires, and the amount of food available, dictates how far apart each individual (or group) must be from one another. This is also affected by how many other species are competing with them for food. However, despite any other factors, individuals must remain within reasonably close range of one other or they won’t be able to locate each other in order to mate and the species will then fail (at least in that area).

The Problem

For the number of different species that I want to have available within a given area, there just isn’t enough room for them all. The various monsters would have to be spaced like trees in a forest to adequately support all the different species of monsters and the creatures they feed upon.

I realize that most people see worrying about things like this as unnecessary nitpicking and prefer to just hand wave the whole issue. After all, how often do players worry about whether or not the eco-system seems balanced and reasonable? Well… actually, I have seen in come up fairly often. But it is always as an aside and no one has ever seemed bothered by it. How troubling is an unrealistic eco-system in a world of magic? Still, I strive to develop a world that makes as much sense as possible. To that end, I want an explanation that allows for the diversity of creatures that I want to have available without having to hand wave issues about their existence.

What I’ve Come Up With

Sometimes, when you are working on one problem, you accidently come across the answer to a totally unrelated problem. So it was in this case. I was working on developing a planar cosmology to displace that provided by TSR and WotC. I have both gods and primordials but gods came first and the primordials were not as powerful nor was there ever any war between them. The primordials created a world, in much the same manner that they created the elemental chaos, that existed within the Astral Sea.

The gods were not pleased and eventually cast this world into another plane, where it would be isolated from both the primordials and themselves. Unexpectedly, the creation of this plane also created a multitude of dimensional reflections within that plane. Each reflection contained an entirely separate world, each similar yet different from the original.

Although there are no permanent links between them (and no known spells to bridge the gap between them), temporary links often occur between the original and each of the reflections. When these links occur, creatures may pass through (and often are sucked through against their will) from the reflection to the original. (Travel is only possible in that direction.)

These links to the other worlds are therefore responsible for a vast number of the monsters in our world. In some cases, entire communities of creatures have come through (or enough individuals or small groups at different times to eventually form large communities). In other cases, a single monster may come through that had never been seen before.

This actually addressed a number of issues I was having:

  • The Feywild, Shadowfell, and Far Realm have always seemed (to me) a bit too contrived, as if they were each individually tacked on as need arose. My approach feels more unified to me, with the Feywild and Shadowfell being reflections that create links with us more often than most, and the Far Realm being a reflection far more different and unusual than most.
  • Occasionally, I want to employ unique creatures. If there is only one (anywhere) then how did it come to be? I don’t want to always have to fall back on making it a rare outsider. These reflections offer an alternative origin.
  • Most importantly, this approach addresses the main issue (described above) relating to the number of creatures necessary to support each species. The support groups, at least in some cases, are not necessary because they exist in a reflection; the creatures themselves are not native to this world.

In short, monsters from endless reflections are continually being transported here from their homes. No eco-system here has to account for them. Instead, these creatures are an assault upon the eco-system.

As before, players probably won’t even question the existence of these creatures. But having a concrete rational behind it all puts me on firmer footing when I want to bring in new creatures. It might even be fun to have a party witness a link forming between the worlds and then see a group of never before seen creatures emerge, looking lost and confused.

The concept of such reflections isn’t exactly new, but the idea of creatures regularly coming through them to our world is. Not only does that offer a somewhat reasonable explanation for the diversity of monsters, but there is the added benefit of using these reflections as the source of extremely rare and unusual items and materials (carried to our world by those creatures): an otherworldly metal possessing unique properties, a white gold ring (maybe not), a technological weapon (with limited and irreplaceable ammunition), or other similarly unusual items.