Notes: The word 'deity' can just as easily be substituted for 'absurdly powerful demon', and 'literacy' for 'linguistic ability'.
[THIS IS A PLACEHOLDER], while [this is a function].
and PSEUDOCODE incoming.!
I'm sure magic has been discussed a million times by now, but just read through it.
It tried to make this magic system feel like a language, in order to make piecing together the incantations feel more natural. And just ignore how i've completely ignored Fortress Mode.
Background: Deities stem power from their worshipers, a deity without worshipers will slowly whittle out of existence.
These deities have a collective form of writing and language, represented by runes.
Runes are randomized at worldgen to keep every new world fresh, and prevent the player from remembering which runes translate to what.
The game would create a rune by taking one of the [VERB]s, [NOUN]s, [TARGET]s or [DEITY]s and randomly attaching gobbledegook to it (slap your keyboard to see what could get attached to the rune representing 'floor').
Runes are found in temples or mages' books, taught by your deity/ies, given as quest rewards, etc.
Literacy skill required to identify unknown runes, and correctly identify the runes you need for a specific incantation.
More specialized runes require higher literacy to identify ([TARGET:BODYPART] as opposed to just [TARGET]).
The syntax of incantations is: [VERB]:[NOUN]:[TARGET]:[DEITY], in which:
[VERB]: eg. [harden/soften], [imbue/extract], [accelerate/decelerate], [heat/cool], ...
[NOUN]: eg. [BODYPART], [floor/ceiling/wall], [gas], [liquid], [mind], [matter], [disease]
[TARGET]:
[self]: (Obviously) makes your adventurer the target of the incantation.
[target]: Use cursor to manually select target.
[area]: Use cursor to select location (diameter depends on deity's power modified by allegiance).
[DEITY]: Will present a list of deities whose names you know.
eg. [accelerate]:[guts]:[target:enemy_goblin]:[Trololo] -> Afflicts the target goblin with explosive diarrhea, as you requested from the prankster-god 'Trololo'.
Asking favors from deities as opposed to ejaculating fire and ice from your hands.
Every time you ask the deities for a favor you run the risk of catastrophic failure or repercussions:
Literacy.
eg. You caused the volcano you're exploring to erupt, because instead of casting [bring]:[item]:[target]:[Lim], you accidentally cast [bring]:[magma]:[area]:[Lim] due to low literacy.
Allegiance: a number between 0 and 1, reflecting how much a particular deity trusts you, and consequently the fraction of your deity's power you can access.
eg. Asking the deity you've actively antagonized to heal your lopped off index finger ended with the deity removing the rest of your hand.
But the deities are lazy bastards and prefer to do as little work as possible, so asking the same favor from a deity in good standing with you would yield no special bonuses over what you've asked of him/her.
A deity's power is a function of the amount of worship they receive.
A cast spell's effectiveness (power for instant effect spells, duration for lingering effects) should then be a function of your deity's power, modified by allegiance.
Individual deities' preferences and associations make spells affecting those associations more effective (or dangerous).
eg. Lim takes the form of a female dwarf, so:
She will happily grant your request to heal a dwarven child that was mauled by a tiger, gaining you an increase to her allegiance modifier for that particular incantation, healing the child more and faster.
Asking her to incinerate your dwarven enemies however would permanently decrease the modifier, increasing the chance of repercussion until you earn her trust again.
Rivalry between deities:
Religious rock-paper-scissors?
Should you somehow be able to kill or banish a deity, it could create a power vacuum amongst the others.