I’m trying to come up with a way of thinking how the existence of various spells might affect the world around them for my NaGaDeMon project. Here’s a first draft of my current thoughts.
Spells like Magic Missile, Fireball, Acid Arrow, and even Shield and Mage Armor fall into a general category of “Warfare” spells in my mind. They change the face of conflict in fantastic ways. Since warfare is a constant concern of the human species, it makes sense for one or two of these spells to be of supreme importance, but having more than one of these types of spell doesn’t have a lot more impact than having a single one, unless you want to go with an uneven distribution of magic. Maybe every army since the beginning of “modern” warfare has trained its soldiers in the use of Magic Missile, but one country has recently developed the ability to add Meteor Storm to their combat repetiore, and so the world is tossed into imbalance, as one nation flexes its newfound military might.
Another option that could be interesting with multiple warfare spells would be different nations using different tactics… Perhaps your Prussian analogue uses Magic Missile exclusively, but your English analogue army uses Acid Arrow. Shorter range, more devestating, and possibly leaves behind polution and damage to the land. These engender two different military disciplines, which can be fascinating to explore. Likewise, if one country has Prismatic Sphere, and the other has Fireball, then it’s likely that their distinctive fighting styles will be different.
Labor Saving Spells, and Spells of Plenty
Labor Saving spells are those which make one or more trades “obselete”. Prestidigitation and Goodberry are two of the more iconic examples, but things like Invisible Servant, Animate Dead, as well as Mending and Message tend to fall into this category as well. These spells disrupt the class structure of human society in interesting ways. Much of human history is based aroung exploiting scarcity of food and agricultural labor. What happens to society if suddenly farming could be perfomed by countless invisible servants. What if ach meal doesn’t even require farmland, but merely a few moments to summon a Hero’s Feast or a bunch of healing Goodberries. How would the wold be different if everyone on their 20th birthday was granted a Wish? How many people would wish for a fortune, and what impact does that have on the economics of a society? While the warfare spells primarily discrupt the military structure of the world, spells of plenty discrupt the economic structure of the worold
Both warfare spells and spells of plenty affect the physical world, in clear and defined ways. But there is a whole set of spells that only affects the minds of others. This covers most of the Illusion and Charm schools. Even without widespread adoption, these spells call into question the concept of “Free Well” and “Seeing is Believing”. While philosophy has wrestled with these questions for centuries, in a world where Major Illusion exists, even if it’s rare or a jealously guarded secret, the idea of being able to examine evidence with your own senses is almost laughable. Likewise, if the spells of Charm or Hold Person are applied, it becomes almost impossible to prosecute a crime. We fought with that question in 1860’s Paris when the Victorian fascination with hypnosis was at its height, and multiple times since then.
On a lighter side, a story centered around a travelling circus of ilusionists and charmers who were among the only, if not the only people with those abilities in the world could be a fascinating one.
Extra-planar contact spells
While there’s relatively few of these, they bear special mention. Without spells for contacting the other planes, we’ll need to consider whether the world we’re making even has other planes of existence. If you can’t summon an elemental, is it even necessary to have an elemental plane? If nobody has ever cast Ethereality or Psychic Projection, should you even include an Etheral or Astral plane in your setting? These spells sit on top of a large set of assumptions about the D&D cosmology that we need to look very carefully at when considering a world of very limited magic, like the one we’re building. If the only contact with the outer planes is Commune, do the people of this world consider the entities they commune with are in any way “physical” and real? On the other hand, if Conjure Celestial is the sole method of contacting the other planes, is it possible that planar travel is strictly one way, wrenching celestial (or fiendish) creatures out of their home, and depositing them in our world permanently? Even Resurrection and Raise Dead start to bring up questions about whether an afterlife is real.
There’s a few other minor spell categories that I’m thinking about as well, and of course many spells can span multiple categories. Raise Dead for example, crosses both the “Extra planar” and “Spells of plenty” categories. Freezing Sphere can annhiliate your enemies, or it can also be used to provide ice to a city in middle of the summer for the midsummer Mojhito festival. This is some fertile ground to plough.