The actual weather conditions that result could be almost anything and may depend on the type of magic fuelling the storm - necromantic energy might create a life-sapping rain or corpse animating lightning, conjuring energy might lead to hails of frogs and transformational energy might create snow that changes the colour of anything it touches. Magical storms might also animate objects at random, transform things, meddle with gravity or do any number of other wierd things. They can also be reasonably expected to interfere massively with any magical working taking place in them - spells might be inhibited, enhanced, dispelled outright or radically altered in effect.
Causing a magical storm should probably be fairly difficult - in some places they may be a natural occurence (probably places where there's a lot of "raw magic" in the environment waiting to be snapped up), otherwise they should probably result from mishaps or side effects of epic magic. They may also result from unfortunate cosmic alignments, the opening of gates to other planes or the death (or birth) of great powers. Another role they can play is as 'magical fallout' in a campaign which takes place in the ruins left behind by some apolcalyptic magical war.
The other 'obvious' cause for a magical storm, especially in a more animist setting, would be the activity of local spirits, either one or more powerful ones with a special interest in weather or a general rampage by many lesser ones. The storm could even take the form of a host of migrating spirits.
Game and Story Use
- This is a hell of a random encounter for your wandering monster table.
- They also make great campaign dressing for the build up to your showpiece adventures.
- Likewise as set dressing for a bad place1 or just some land of great magical potential.
- You could also run a fantasy 'storm chaser' campaign where PCs run about after magical storms studying them, either to learn how to harness them or avert them or possibly to find out why they've suddenly started.
- If they're not normal in your campaign, their sudden appearance may tie into a prophecy or link to some time in the past when they last occured.
- Someone may develop a technique for harvesting them - the BBEG would be obvious, but it might just be a hubristic wizard of far less malevolent intent or an artificier who wants to use all this free energy to power his devices … or even just someone looking to bleed the power off and defuse the storm. What are the results of consuming so much wild energy?
- In the face of a spirit storm, you're going to need one hell of a shaman. A poweful shaman might be able to pacify - or at least re-direct - the angry spirits and might even be able to bind some or all of them into a fetish. Faced with a mob of homeless spirits he might even be able to win some valuable allies amongst the newcomers if he is able to settle them in to the local area.
- What is so terrifying that it can make a whole host of spirits migrate?
- Of course, an animist tribe might bring a large number of spirits along with it as it migrates - if they were suitable abrasive, the storm might move alongside the migrating tribe.