On further reflection on the works that serve as inspirations and references for my new setting I have noticed that my unspoken assumption of immortal supernatural creatures coming from another dimension is really something that comes mostly from the context of Dungeons & Dragons, but is otherwise actually quite uncommon. Much more often you find magical creatures living in remote or hard to reach places in the very same world as the mortal peoples, such as below the earth, on top of mountains, or inside great forests and swamps. The idea of a separate spiritworld is not that uncommon in mythology, but in traditional hero tales the land of immortal spirits are usually reached simply by walking there, even though the journey can be very difficult. I actually find that much more intriguing and I feel that it meshes better with the northeastern European style I want to go with and the noir feel that dominates most of my favorite works. It’s at the same time more low magic and also more deceptive and ambigous.
But at least for my own peace of mind I can’t let it simply stay at that. For my own sense of believable plausibility, the world needs to have some kind of underlying structure that provides a credible reason why magical creatures don’t simply sweep away the mortal peoples and why civilization isn’t forever expanding into every last corner of the world. (The later is of course completely arbitrary. I’m simply not a fan of the traditional convention that civilization and progress make spirits into a dying race of helpless victims.) Central to my approach is the old Hill Cantons concept of Corelands, Borderlands, and the Weird, which I think I’ve been references a couple of times in the past already. The idea behind it is that there are regions in the world where the forces of magic are very weak and regions where they are very strong, and between them lies a region of intermediate magical influence. Spirits and other magical creatures are at their strongest in the Weird, and it’s a place where mortal sorcerers are at their most powerful as well. In contrast, Corelands are very weak in magic, which decreases their power significantly and makes them much more vulnerable against the weapons and overwhelming numbers of the mortal peoples. Spirits exist and magic is possible, but their strengths are a far cry from what they are in the Weird. This all leads to a natural balance where both mortals and spirits have nothing to worry from each other within their own domains yet are mostly unable to expand their influence.
But obviously, this does not apply to the Borderlands. In Borderlands, spirits are of sufficient strength to pose a real threat to settlements, but they more often than not lack the power to overcome the wards and resist the rituals that village shamans and witches use to protect them. Life in the Borderlands is much more precarious than in the Corelands, but villages and even small towns still thrive when they can come to arrangements with the local spirits that inhabit the land.
A weak ago I was watching a documentary on the Little Ice Age and how sudden, relatively minor changes to the climate had a huge impact on European history from the late Middle Ages for centuries to come. In many places it was like the land and the weather where slowly but steadily forcing people from the homes they had inhabited for generations. It has quite interesting storytelling potential, and applying it to the situation at hand I’ve decided to not have the confines of Corelands and the Weird being eternally fixed, but to slowly shift and change over the course of centuries. Regions that have been home to great cities for over a thousand years might find magic growing stronger and local spirits gaining in power, leading to a collapse of civilization in the matter of a few generations and returning the land to a sparsely inhabited wilderness filled with supernatural wonders and horrors. Similarly, other regions can become safe to settle and as the first people are entering the new Borderlands they find the ancient remains of civilizations from ages past.
But climate is the patterns you have over the course of many years. Weather is what you have today. While general levels in magical energy increase or decrease only very slowly over time, short and sudden surges of supernatural power rolling in from the Weird can happen much more unexpectedly. Sometimes these magical surges can swell up and recede over the course of several weaks, while at other times they come and go within only a matter of hours. Borderlands are the most vulnerable to such sudden temporary expansions of the Weird, but in more extreme cases they might even reach far into Corelands. To sorcerers in the Corelands these are great opportunities for the performing of powerful rituals, but for everyone else they are often catastrophic. Not only do attacks by emboldened spirits become much more common while their power grows to new heights, the surges in magic can also be accompanied by actual storms of supernatural power. Often they take the form of great thunderstorms or blizards, but can also appear as floods, volcanic eruptions, or series of earthquakes. More often than not, such natural disasters are accompanied by surges in magic, though sometimes the effects are much less obvious at first.
Other potentially disastrous consequences of a magic surge are the sudden growth of hostile vegetation or the dead rising from their graves. And there is always a great chance of spirits from the Weird following in the wake of such magical storms. The most famous example is the Wild Hunt, a horde of fey riders who chase after snowstorms to ride deep into the Borderlands and raid for slaves to be taken back to their realms.
While mortals are usually not sensitive to surges of magic in the environment around them, there are several warning signs that point to immenent trouble comming to their lands. The earliest warning is the appearance of tiny glowing sprites that come seemingly from the ground or underbrush at sunset in the days preceding a magical storm. These are a common sight in the Weird but are only seen in the Borderlands in times of increased magical energy. When the magical powers are at their full strength they lighten up the night sky with the green and blue glow of auroras. These are no more common in polar regions than in tropical ones but are consistently present in the skies above the Weird.