Racial Spell Cost Modifier

Every race has a racial spell cost modifer associated with it. There are three kinds of spells, arcane (mage/wzd/sor type), divine (cleric type) and psionic.

A negative modifier means the spell cost is lower.

Effective Mana

Note that the following shows the spell cost modifier. We can define the effective mana as the mana a human would need to cast the same amount as a particular race. If x is the racial spellcost modifier (in percentage), then the effective mana is 100 / (100 - x).

For example, a 25% spellcost reduction for sprite translates into 33% more effective mana.

Effective mana is the more directly useful notion, since finally, that's what determines how much you can cast.

Worship

The effect of worship on spellcost is multiplicative. For example, a bhyss sprite will have spellcost reduced by 10% x 75% = 7.5%. So, its spellcost modifier is -(25 + 7.5)% or roughly -33%.

The values

Legend
Divine
Legendary
Great
Good
Average
Below Average
Bad

Creatable Races Spell Cost Modifiers

Race	Arcane Modifier	Divine Modifier	Psionic Modifier
Centaur	-10%	-15%	-10%
Deep Gnome	-7.5%	-5%	-5%
Draconian	none	none	-5%
Drow	-12.5%	-10%	-10%
Duergar	?	?	-5%?
Dwarf	+5%	-10%	none
Elf	-12.5%	-10%	-10%
Ent	?	?	?
Firedrake	none	none	none
Gargoyle	-15%	-10%	-10%
Giant	?	?	?
Gnome	-7.5%	-5%	-5%
Goblin	+10%	+10%	+10%
Halfling	?	?	?
Half-Elf	?	?	?
Half-Orc	?	?	?
Harpy	?	?	?
Human	none	none	none
Imp	average	Bad	Good
Kobold	?	?	?
Kzinti	none	?	none
Lizardmen	none	none	-5%
Ogres	?	?	?
Orc	+10%	none	+10%
Troglodyte	+25%	+25%	+22.5%

Remort Races Spell Cost Modifiers

Race	Arcane Modifier	Divine Modifier	Psionic Modifier
Demonseed	-12.5%	-10%	-10%
Dragon	-10%	-10%	-15%
Golem	?	?	?
Griffon	?	?	?
High Elf	-15%	-15%	-20%
Hobgoblin	?	?	?
Minotaur	?	?	?
Miraar	none	none	-10%
Sprite	-25%	-25%	-25%
Troll	+5%	+10%	+10%
Tuataur	-10%	-10%	-20%