Calculate
Name
Calculate
Type of Magic
Priest
Spell Level
1st
School
Greater and Lesser Divination (House Sextus)
Sphere
Numbers
Reversible?
No
Range
0
Components
Material, Somatic
The material component for this spell is a miniature abacus of ivory worth at least 100 gp. It is not consumed in the casting of the spell.
Duration
Instantaneous
Casting Time
4
Area of Effect
The caster
Saving Throw
None
Effects
By means of this spell, the priest can accurately estimate the chance of success of one specific action, such as climbing a dangerous cliff, making a trick bowshot, crossing a burning room unharmed, or even striking an enemy. The action in question must be one that would normally be resolved by a die roll, but the priest doesn’t have to be the person who attempts the feat; he can use Calculate to estimate the odds for anyone taking an action in his sight. The priest has a 70% chance, +2% per level, of making an accurate estimate.
If successful, the DM reveals to the player the action’s chance for success or any modifiers that may be in play. For example, he could reveal a particular opponent’s Armor Class or THAC0, the saving throw an opponent would require in order to save against a particular spell cast by the priest or the priest’s wizard companion, or a character’s chance to open doors, bend bars, or use a thief ability. The priest could even Calculate his odds for actions that might be resolved by a die roll or DM caprice, such as his chance to avoid detection by hiding behind a rock. This spell takes into account factors that the priest himself may not be aware of, so from time to time a character may receive some very confusing results from this spell. For instance, if the priest doesn’t know that an orc chieftain is actually a polymorphed tanar’ri masquerading as an orc, he may be astonished to learn that the “orc” has a THAC0 of 7!
If the priest fails his calculation check with a roll of 99 or 00, his calculation is wildly skewed in a random fashion.
