Editing Geos:Fate-Fudge Rules:Magic:Imperial Magic

==Using Magic in FATE-Fudge==
	In order to reliably cast a spell, a character needs skill in a school of magic, or a magical text.  Some creatures also have specific powers, but these aren't considered 'spells' per se.
	
Casting a spell from a scientia magia the character knows is by far the most reliable method.  The player declares they're casting the spell and rolls 4dF against the modified difficulty, applying the relevant magical skill.  A Fate point must be spent on casting a spell, unless it is a counterspell.
	
If the character has a tractus magia that would be relevant to casting the spell, she gets a +1 bonus to her effective magical skill.  No more than one tractus may be applied to any single spell.

===Base Difficulty===
	The simplest effects – creating a light breeze, bringing rain down from a cloudy sky, making a person friendly towards you – are the easiest.  These affect the world in a limited and natural way – they're effects that could happen, even  if somewhat unlikely.  These have a base difficulty of 0, and may be made permanent without using static thauma if doing so would be natural.  So a breeze or rain couldn't be made permanent (at a base difficulty of 0, at least), but a spring could be called from a ditch in the desert or a person's attitude permanently shifted.

	Simple natural effects in natural circumstances that wouldn't normally happen spontaneously, like causing a bridge to collapse, or setting wood on fire, are more difficult.  Calling a thunderstorm in a desert would also qualify because, although it could happen, it's so plainly unnatural that something unusual must have called it.  These have a base difficulty of 1. 

	Natural effects in alien circumstances are more difficult still.  Coming through a burning building unscathed is an example: while it's natural not to be burnt, it's not natural in this specific circumstance.  Growing a lion's claws would count, too.  The base difficulty for these effects is 2.

	Unnatural effects have a base difficulty of 3, regardless of circumstances.  Creating a house ex nihilo or growing wings sufficient to fly would be an example – although wings are natural, big wings aren't.  

	Effects that are completely alien to reality have a base difficulty of 4 or more.  Creating cold fire that freezes what it consumes, being in two places at once, or are completely alien things.  Not only are they unnatural, they're also plainly impossible by the commonly understood laws of nature.<!--  @todo:  permanency rules-->

===Modifying the Difficulty: Caster===
Casting a spell typically takes one turn, during which the character can't do anything else, other than take a supplemental action.  A caster can defend herself against attack (and take other free actions) without penalty.  If the result is an injury, the difficulty of the spell increases by the level of the injury; if the result is a situational consequence, one or more of the aspects inflicted may increase the difficulty of the spell. <!-- May edit this -->

	A character can take extra time for a +1 to skill.  How much time is necessary depends upon the spell's base difficulty:
		* Base difficulty 0: one minute
		* Base difficulty 1: one hour (or scene)
		* Base difficulty 2: one day (or game session)
		* Base difficulty 3: one week (or adventure)
		* Base difficulty 4: one month (or longer)

	Casting a spell reactively (i.e., as a free action) increases the effective difficulty by 2.  Any number of spells can be cast during a combat turn.  However, the consequences of failing are potentially extreme, since the caster is cutting out safeguards and self-protective measures.  Failure to successfully roll the effective difficulty doubles the negative consequences.

	Casting a spell without using gestures adds one to effective (not base) difficulty.  Casting a spell with only gestures adds one to the effective difficulty.  A caster cannot do both, unless they are channelling natural magic – something normally impossible for humans.

	Using a number of measures of static thauma equal to the base difficulty of a spell adds one to effective skill.  Additionally, if the spell is potentially permanent, a similar amount of thauma can be used to seal the enchantment.
<!-- Adding to a spell adds to modified difficulty, caster pulling funny stunts alters effecive skill-->
<!-- Distraction, etc., adds to mod diff.-->
<!-- Aspects can be invoked-->
	
===Modifying the Difficulty: Spell===
	Every aspect the character wishes to add to the spell increases the modified or base difficulty by one.  The modified difficulty is increased if the effect is merely to be enhanced – made bigger, better, longer, more powerful.  (Multiple aspects may be necessary for extreme effects.)  If the spell is to be fundamentally changed, or if is to have secondary effects, add to the base difficulty.  

	Another reason to add to base difficulty would be if the spell does not properly fit into the caster's magical theory, or if the caster should know something she doesn't.  For example, casting a spell to inspire someone to creative genius is normally a Mentem spell – but creativity is an aspect of fire, so the GM may specify that several levels of Ignem would be necessary.  If the caster doesn't have the requisite levels of Ignem, a +1 to the base difficulty (or +1 per missing level of Ignem) would be appropriate.
<!-- GM may also modify spell dif for Rping and for play balance. -->

===Casting the Spell===
	Once the difficulties are determined, the caster should roll 4dF and add her effective skill.  Compare this to the base difficulty.  If the roll is less than the base difficulty, the spell fails completely.  Otherwise, for every point the roll exceeds the base difficulty, the GM adds one aspect to the spell, using the caster's chosen aspects first <!-- opt: GM chooses randomly, weighted towards player's desired aspects -->.  These aspects should generally make the spell more powerful or dramatic; they are, after all, the direct result of the caster's competence and caution.  

	On rare occasion, these beneficial aspects may be a nuisance.  The caster may find a spell expanding past the bounds he desires, or conjuring a much smarter and devious monster than is wise.  When the GM does this, he should offer a Fate point to the player as compensation.  The player must spend a Fate point of his own to cancel the undesirable bonus aspect, or accept the Fate point from the GM.

	If the spell roll is less than the modified difficulty, add one aspect for each point the roll missed.  These aspects should be negative, reducing the power and effectiveness of the spell.  If the player doesn't like these aspects, she can use a Fate point to counter them (one Fate point per aspect.)

<!-- Number of free tags by success? -->

<!-- Complete spellcasting example: -->

<!-- Maintaining spells -->

<!-- Other aspects (e.g., Air talent, extensive spell list) -->

==Relevant Links==
* [[Geos:Game_Universe:Magic|The Imperial theory of magic: an introduction]]
* [[Geos:Game_Universe:Magic:Imperial_Laws|The limits of Imperial thaumatology]]


Please note these rules are subject to change.  I'm working on it, dammit.