How can I design my spell system to stop my casters from being overpowered?

Question

Battle magic works by coalescing the mana inside your body and forcing it out your hands into the spell you wish to conduct. This is physically and mentally demanding, and the user must maintain upmost concentration during the process, or they can damage themselves. This makes this a dangerous for of magic to use.

In recent decades, a workaround has been developed to make the process easier and safer. Tattoos, which are sigil meant to represent the spell being done, are magically formed on the body and only appear during the casting. These sigils absorb the mana into themselves and help the caster coalesce their mana quickly and efficiently. These sigils are permanent, but fade away when not in use.

The drawback is that these tattoos force the flow of mana into a particular "shape", which limits the caster to that particular spell. The caster cannot use any other forms of magic or spells of battle magic until that tattoo is removed. Therefore, it provides quick and safe use while limiting the pool of spells.

This is my issue. If a caster wanted to use a very powerful battle spell, such as a tornado of fire, they could easily tattoo these sigils magically to themselves. This can make them overpowered, even with the limitations of these sigils.

How can I limit casters from easily using these powerful spells?

Answer 1

Overpowered but useless

The tattoo makes it easy to cast the spell, tattoos are hard to remove in the field. In fact the tattoo makes it too easy to cast the spell and any attempt to cast might trigger the tattoo. So your great magician has the fire tornado tattoo, and now any time he tries to cast anything fire related, there's a reasonable chance he'll cast a fire tornado. Trying to light a camp fire, fire tornado. trying to light the torches in the castle, fire tornado. Trying to light the way to the toilet in the night, fire tornado. Totally overpowered, total liability in any other situation.

Then you just never put him in a situation where a fire tornado is useful.

Answer 2

I have two ideas, which can easily be combined:

1. The tattoos take time to form, and just like regular battle magic, you need to concentrate in order to form them. The tattoos for more powerful spells take longer to form, so the formation could be interrupted by another caster using a more basic spell that's quicker to set up.
2. More powerful spells require larger tattoos, limiting the number of sigils you can have on your body at any given time. So you could have a handful of really powerful spells, but potentially end up in situations where none of them are useful; or you could have loads of weaker ones and out-maneuver foes through versatility and unpredictability rather than brute force.

Answer 3

Depending on the technology available to your casters, it may be a specific skill set to make really effective sigil tattoos that requires years of study, or require assistance or a large time commitment.

The larger/more powerful the spell or sigil is the longer it takes to fade due to the increased amount of mana passing through them, making the casters vulnerable for longer periods of time.

Or the more powerful the sigil, the more intricate the necessary tattoo. Making it that much easier to mess up and potentially backfire on the caster, which brings in a 'the bigger the spell the bigger the risk' equivalency.

Answer 4

The Tattoos are like dams of a river (spell).

The larger, more complex the spell, the bigger the tattoo. Each tattoo have a wind-up and cool-down period.

The spell (the riverbed between the dams) has to be filled with mana. This can't be done mindlessly. Dumping too much, too soon would destroy the dam and the river would flood outside. Though it is easier than natural spell casting which is a river without dams.

The larger the spell, the more they have to be filled. This is the process of the tattoos appearing. The dams come into play as the river floods outside its normal route.

The tattoos MUST fade as well, after each usage. They restore themselves. Like dams, which were barely able to hold on, they can't handle an other flood right away. In case of small rivers, this time is short, barely noticeable. In case of huge, wide rivers it takes a lot of time and even maybe some extra repair work.

Answer 5

How about the tattoos make magic easy enough to use that even non-mages can use them for weak magical effects. if the rank and file soldiers - not to mention elite troops - have access to faster healing, magic resistance, and increased speed, strength, stealth, etc... A mage can toss out fire tornadoes but they might get taken out by a tattoo enhanced assassin, or the troops on the other side might be fire resistant.

This doesn't restrict the use of tattoo enhanced magic for your casters as much as balance the playing field a bit so they aren't as overpowered relative to other kinds of fighters.

Answer 6

Mana Overload

Perhaps the human body simply isn't built to be a conduit for vast amounts of Mana. A spell as powerful as a fire tornado would probably require a lot of Mana to cast, meaning the spellcaster needs to both pull an enormous amount of mana into their body, and then send all that mana out of their body in a very short period of time.

Depending on how mana works in your setting, this could be comparable to building up an enormous electric charge in the body, and then releasing it quickly- that is, it takes a long time to build up, and releasing it all too quickly can damage the user even if they're properly focused.

Alternatively, Mana could require the body's own energy to store and release, meaning that a few large spells would leave the spellcaster physically exhauseted, and very vulnerable. TV Tropes refers to this type of limitation as "cast from calories".

Answer 7

The casters didn't actually 'cast' the spells, they just 'use' them. So they can't master them to improve, like change from fire ball to fire arrow, fire bullet, etc... And since those tattoos cast spells outside the body, a lots mana vaporized to the environment.