Welcome to Part 11-3 of my World Building blog series :D I’ll be covering just about every topic I can think of that goes into world crafting. If you have any topics you’d like me to write about, please let me know :)
Combat magic can be pretty expansive and basically applies to any way that magic is used for offense. Like we discussed in the Magic – The Basics, you should already have figured out where your magic comes from and what the basic limits are. From that point we can get into the meat of combat magic.
Magical weapons show up all over the place. Notable examples are King Arthur’s Excalibur, Thor’s Mjölnir and the Sword of Gryffindor. These are weapons of war that either have a magical origin or have been enchanted somehow. The origins and enchantments are going to heavily influence how the combat magic associated with the weapon works. Does the weapon augment the user’s power or does it have it’s own unique ability separate from the user? Is it able to be used by anyone or only the one it was created for? Is there any contract in place for the use of the weapon? Some magic weapons have a level of sentience, does that apply to the ones you’re creating? If a weapon is only able to be used by one person, how does it know someone else is trying to use it? What happens when someone else does try to use it? Can the magic of the weapon be depleted or completely drained? If so, can it be replenished and how? Is the weapon always in it’s battle form or does it have an alternate form that makes it easy to transport (ie. Percy Jackson’s sword turns into a pen when it’s not in use)?
Protective magic also features fairly heavily into combat magic. This is where you’ll run into things like magic armor, protective amulets, etc. Consider these with the same questions as above. Whatever way you end up deciding to use items like this, be consistent. You’re not going to want something that’s so overpowered that it takes away the stakes. If your characters aren’t in danger when they get into a battle, you’re going to lose tension because no one will be worried about them. Figure out the hard limits of the magical items and stick to it.
Combative spells are pretty well known, especially thanks to media like Harry Potter. The wand itself isn’t a magical weapon since it’s main purpose isn’t combat. Spells, charms, etc. can be used combatively, but are also not inherently about battle. Once you’ve done the leg work to figure out the magical basics, you’ll be able to determine whether or not spells are a viable option for your story to use for combat. This will be dependent on how much work is involved. If you’re doing the point and zap method like Harry Potter then it’s probably fine, but if you’ve elected to include ritual, ingredients, etc. then you’re probably not going to be hauling spells out on the battlefield.
The best example of combative elemental magic I can think of is probably Avatar the Last Airbender. Your characters are limited to a highly specific type of magic, each suited for it’s own unique type of combat. You can modify most types of magic to be fairly suitable for combat, but elemental is the example I’m working with. How many branches of this magic are you going to have? There’s base elements of earth, air, fire and water (expanded also into lava, sand, metal, flight, lightning, blood, ice, etc.). You can expand them further or introduce other varieties light/dark, technology, telekinesis, teleportation, energy, gravity, time, etc. Which options are available to your characters? Can people wield more than one type? Do different types have different levels of energy draw? How many times can a person use their magic before they cause damage to themselves? Can they be hurt by the element they’re wielding?