These are the basic guideline calculations that the GM should use to tally a casting difficulty on spells.
No spell can have a positive spell difficulty, the easiest spell possible is at a zero, or exactly what the skill of the character has in spellcasting.
Overall the details and limits combine and compound to produce a single difficulty modifier result.
All In Area (-4)
Animal (-3)
Area : Room (-4)
Area : Structure (-6)
Area : Boundary (-8)
Multiple Targets (-2)
Plant (-2)
Object (-2)
Other Being (-4)
Other Spell ( 0)
Self ( 0)
Sub-set of Target Type** (+1)
Twice Caster Size or More* (-2)
*Does not apply to spells bought with Area already included
**Example : Only Works on Dogs (Animal Subset)
Arcane Connection Targeting Optional (-4)
Instant Effect ( 0)
Continuing (as per Spirit Duration) (-4)
Triggered By Event in Future (-6)
Repeating added to Trigger (resets) (-4)
Permanent Changes (-8)
Bind or Block (-5)
Communication (-2)
Control (-6)
Creation (-8)
Destruction/Damage (-8)
Enhance (-4)
Gate (-10)
Illusion (-2)
Influence (-2)
Information ( 0)
Movement (-4)
Precognition (-8)
Protection (-4)
Repair (-4)
Retrocognition (-6)
Scrying/Distance Observation (-4)
Summoning (-8)
Teleport (-8)
Transformation (Minor Change) (-4)
Transformation (Greatly Change) (-8)
Spirit/2 of Effect ( 0)
Spirit of Effect (-2)
Spirit * 2 Effect (-4)
Arcane Connection Needed (+2)
Concentration (Defense 0 while cast) (+2)
Dance/Full Body Movement (+3)
Gestures (+2)
Incantations (+2)
Must Be Caster's Only Active Spell (+3)
Only Two Mystic Senses (+1)
Single Mystic Sense Only (+2)
Extra Time : Extra Action (+2)
Extra Time : Full Minute (+4)
Extra Time : Ritual (Varies) (+6)
Specific Time of Day (ex : Noon) (+4)
Specific Time, Day of Month (+6)
Specific Time, Day of Quarter (+8)
Specific Time, Day of Year (+10)
Specific Location (cemetary, beach) (+2)
Specific Location (singular) (+4)
Specific Environment, Minor (Night) (+2)
Specific Environment, Major (Storm) (+4)
Specific Environment, Severe (Eclipse) (+6)
Minor Foci/Tool (ex: Knife, Chalice) (+2)
Major Foci/Tool (ex: Altar, gemstone) (+4)
Severe Foci/Tool (ex: Relic of Saint) (+6)
Multiple Foci of type needed (+2)
Expended Foci (ex: bottle of wine) (+2)
Minor Living Sacrifice (own blood, bird) (+2)
Major Living Sacrifice (dog, virginity) (+4)
Severe Living Sacrifice (Cattle, person) (+6)
Additionals of same type needed (+2) (+2)
Specialized Sacifice Type (+2)