This seems like a glaring oversight, but what are caster levels? Do characters only have one score called caster level just like sneak attack? Why do most classes not state what their caster level increases are? Do all arcane and divine caster levels stack? What about just all arcane caster levels?
I have been playing Spheres of Power lately and it clearly defines when caster levels are gained and how they stack with caster levels from other classes (at least other SoP classes). It got me wondering about original caster levels. So I started doing research.
Under the magic rules for caster level
A spell’s power often depends on its caster level, which for most spellcasting characters is equal to her class level in the class she’s using to cast the spell.
Paladins are one of the exceptions which within their own rules state what the CL of the class is suppose to be.
Through 3rd level, a paladin has no caster level. At 4th level and higher, her caster level is equal to her paladin level – 3.
But the core casting classes of Cleric, Druid, and Wizard have no statement on how their CL increases as you progress in the class so I guess we are forced to assume its equal to the levels in that class.
Under the common terms is another definition of caster level
Caster level represents a creature’s power and ability when casting spells. When a creature casts a spell, it often contains a number of variables, such as range or damage, that are based on the caster’s level.
Finally we have the Mystic Theurge which does seem to have mention that classes have their own isolated caster levels.
This essentially means that he adds the level of mystic theurge to the level of whatever other arcane spellcasting class and divine spellcasting class the character has, then determines spells per day, spells known, and caster level accordingly.
As shown in the FAQ/Editors Note
The increase to his spellcasting level does not grant any other benefits, except for spells per day, spells known (for spontaneous casters), and an increase to his overall caster level.
So would a cleric 1 wizard 1 have an overall caster level of 2, or would each class have their own caster level? What about a cleric 1 and druid 1?