Quote Originally Posted by GreatWyrmGold View Post
Random tangent: Given how often scientist-type characters are "punished" for trying to exploit or work around the rules of magic and/or meddling with forces they don't understand, I'd like to see some magicky-type characters get similarly punished for breaking laws of physics that they don't understand. Sadly, I can't think of anything good for asymmetrical reflectivity...
Partial thermodynamics: For any force they create magically, they have to simultaneously create a specified fraction of the opposite. For example, flying magically would require them to exert a fixed fraction of their weight, increased when they move based on how fast they move, on something else. If nothing is in range, it's omnidirectional pressure on them. What's 10 atmospheres of pressure in PSI? Because at that point, it gets dangerous. And making a single cup of water boil might well cause instant hypothermia, and you'd flash freeze before getting anywhere with slagging iron.

Traditional magic users don't really notice because they've institutionalized dealing with it by applying this opposite force to the target of the spell, weakening it in exchange for having no backlash issues from it. The "muggleborn" who started popping up during the population explosion of the Industrial Revolution don't know this and might well have a high fatality rate from stuff like causing massive internal damage from tossing lightning and suddenly having a large positive charge in their body. Which means suddenly missing a bunch of electrons that are probably holding spmething important together.

However, there's advantages to this, too. If you can cast spells that do opposite things, like applying heat and cooling, then they end up much stronger due to venting the opposites into each other. You "pay off" the heat by upgrading the cold and vice versa. But you have to fully recognize what's going on to make it work out for even just lightning bolts or flight. Which means knowing about the science behind the forces involved.

A fun thing to do with portals in this case is to have them work by shortening the distance between two geometric planes, so the opposite is lengthening the distance, meaning you can delay an enemy charge while hastening an ally's movement. And intentionally-sloppy magic can increase the opposite force, allowing you to Fireball one person as you Cone of Cold a second.