We're making a hard magic system for our tabletop game. That is to say, the magic system has restrictions it can't circumvent. This is both important to the world and to the gameplay, since the players are also bound by these rules. It also means that we can allow custom spells without game-breaking consequences. So, here's the rules of the system in the game's lore, and the gameplay rules we have so far. Then I'm pretty sure I'm going to need help with the custom spell rules.
Lore rules:
Ethers:
The ethers are the basis through which magic functions. The ethers are physical forces, which are manipulated to produce results. This is not exactly a new concept in and of itself, and it's not supposed to be. There are two ethers. These are the spirit ether and the aura ether.
The spirit ether manifests as mass. Lifeforms can exist predominately in this ether, and despite having little physical matter in them appear to have mass and physicality to them, interacting with gravity and physical objects as if they themselves were physical. Such a creature could, with a simple change to how they're interacting with their ether, massively increase or decrease their effective mass without actually gaining or losing matter. These creatures are naturally attuned to telekinetic effects, which both allows them to use such abilities better and makes them vulnerable to them.
The aura ether manifests as light and magnetism. This light is not necessarily visible, and in terms of visible light many aura spells either don't significantly affect the level of visible light or actually reduce it. Auras are produced by life and can both feed and destroy life, but it's too volatile for life to be composed of it. The workings of this ether can't be as complex as those of the spirit ether, but it can produce far more raw energy and especially can produce it faster.
But what's most notable about these ethers is that they interact. Clumsily, but they interact. This allows each of them to produce some effects they shouldn't be able to have, through creativity. The spirit ether can't create light directly? No problem, you can contain and excite a bit of air until it glows from heat. The aura ether can't repair bodily injury? No problem, send information and energy to the person's body, and its spirit component will repair the damage. Aura can't do everything spirit can do, but spirit can do everything aura can do. However, spirit is terrible at doing the things aura can do, even if it can technically do them.
ALL classes use magic in this game, but they might only use spirit magic (champion, bard, shaman and psion class groups), only use aura magic (soldier, warrior, rogue and expert class groups) or both (cleric and mage class groups).
Conservation of Energy:
Simplest rule first. Magic exerts energy, and it requires energy. The form of the energy may change from input to output, but the core premise "Energy In == Energy Out" remains the same. Input energy works differently for different classes, but there is always a cost associated with magic. Generally, your class has a resource it uses to cast and this resource is replenishable in some manner. Additional energy is put in to catalyse spirit spells, which becomes waste energy once it's done starting the reaction. Additional energy is not required to catalyse aura magic, but movement (and thus energy) is required to control it.
Spirit casters play off their connection to the spirit ether, which is in the form of an imprint their body leaves on that ether. This damages the imprint and disrupts their connection, but it restores itself over time. That is to say, you have a number of spirit points, spells cost spirit points (called something different for each class), and these regenerate. Very simple, very easy, requires no maintenance and is ready to go again in a matter of minute. Too bad the pool is tiny.
Aura casters play off their connection to the aura ether, which is in the form of the aura their body emits. This consumes energy otherwise needed for bodily function, which taxes the body much like physical activity. This is regained the same way as regaining energy from physical activity. That is to say, their spells cost aura points, but these points do NOT regenerate and need to be manually restored by food, drink and rest. That also means that depleting your aura leaves you physically tired, which penalises your stats the same as if you'd worn yourself out through physical exertion. However, the pool for aura casting is far larger (literally ten times the size) of the pool for spirit casting.
All characters have both spirit and aura point pools, even mundane animals that can't use magic. Additionally, many spells will have both an aura and a spirit cost.
Methodology of Interaction:
The methodology of magical interaction is the mindset classes use to interact with the ethers to produce magical effects. These are the passive method, the talent method, the rote method and the analytical method. This determines attributes used (if any) and how spells are learned (if they can be).
In the passive method, you don't actively use the ethers to produce magical effects, they are beyond your conscious control. They are triggered unconsciously by stimuli (or are passive), and you can usually act to create this stimuli if you recognize it, but you are more "tricking" your powers into activating than you are actually using them. For example, blood knights (from the warrior class group) have the "bloodlust" ability. When they inflict a bleeding wound, their aura activates to detect their victim and guide their hand, giving them advantage on attack and damage (roll twice and use the higher value) against that target in exchange for aura, until they fail to inflict another bleeding wound.
In the talent method, a caster is naturally talented with magic and doesn't need to learn how to use it. They decide what they want to do, and they do it. They use the charisma stat to determine the power of their magic, making this most effective in younger casters. Talent casters control their magic, but they don't really understand it and it's predominately driven by emotion. As a result, talent casters cannot learn spells. Talent casters must create spells of their own. A sorcerer (mage class group)'s spells, for example, are created by that sorcerer. If a sorcerer player wants to shoot flames in a cone in front of them, they make a cone fire spell, and get to determine its range, damage and additional effects (within the custom spell rules).
In the rote method, a caster is taught by another caster how to use magic through rote memorisation, they trust in their instruction and then they do it until it works. They use the faith stat to determine the power of their magic, making this most effective in older casters. Rote casters control their magic, but they don't really understand it and it's predominately driven by conviction. As a result, rote casters can only learn spells. They either rely on simple abilities, or they must be taught spells by somebody else who knows them, and that somebody must be a member of their class group for it to work. For example, a priest (cleric class group) may know a spell called "shield of faith", but in order to know "shield of faith", they would have to be taught "shield of faith" by somebody who already knew it. This could be another priest who learned it from somebody else, or it could be an evangelist or archivist (also cleric class group) who actually invented the spell, but the point is somebody had to beat it into their head. (Probably in some sort of religious institution, one would imagine.)
Finally, in the analytical method, a caster learns the principles underlying the casting of various spells, and learns how to make new spells based on them. They use the intelligence stat to determine the power of their magic. Analytical casters control their magic, and to some extent do understand it and use that understanding to shape it. As a result, analytical casters can both learn spells and make their own. However, in order to make spells, they need to learn spells first and they can only build spells from effects that are used in other spells. IE: A wizard that is taught a cone cold spell, a line lightning spell and a spread fire spell can make cone, line and spread spells that deal cold, lightning or fire damage.
How We Actually Need Help:
Custom spell rules:
We haven't written the custom spell rules. Jeremy's busy this week, and I want to get started. Since custom spells are the backbone of this system, firm rules need to be made for them fast before more work can be done. I don't need to get it well refined, that's Jeremy's job, but I want to get an outline done before he gets back on Monday. And personally, I'd appreciate any help I can get. I'm going to post the basic framework below, and then it's a matter of figuring out effects that can be achieved with this magic system and assigning reasonable-sounding values to them. Jeremy will fine-tune the numbers later.
- Spells have a level from 1-5, and cost a number of points to cast equal to their spell level squared.
- This is NOT equal to the number of points allowed to build a spell of this level, which is as of yet undetermined but will be linear.
- Spells can be targeted, affect a line of squares, a cone, or a spread.
- The longer the range or larger the area of effect, the higher the cost.
- Targeted spells have the lowest cost, and it grows linearly based on their range.
- Line spell cost increases linearly, cone spell cost grows by the square of their range, and spread spell cost grows by the cube of their range.
- Spells can also be concentration or fire-and-forget.
- Concentration spells drain points each round while active. They have no listed duration, and drain the given value per round.
- Fire and forget spells have a set duration, and do not require the caster's attention. They have a flat cost.
- Separate damage types face energy resistance separately, but each one gets a caster ability bonus separately.
- Spells that fire multiple shots should be a thing.
- So should spells that have effects like advantage (roll attack twice and use the higher one).
- Also, spells with increased save DC.
- And spells that are better or worse against specific targets, such as spells built to damage spirits specifically.
- Spells that provide a buff have a type, such as "area", "personal", or "weapon". You may only have ONE buff spell of each type active at any given time.
- I'm sure there's more things I haven't thought of I need to come up with rules for. That's part of why I'm posting this.
- That's literally all I have on these right now. I'll need to get details in the morning.
Brainstorming on ideas for what effects to add for each ether type is also appreciated. I may have to clarify a bit more on how each ether actually affects the world, though, because a lot of things are either right out or would have to work in very specific ways. (IE: Teleportation is right out, which means summoning is too.)