Quote Originally Posted by Andreaz View Post
Extra Spell adds to your spells known list, right?
Wizards don't have spells known.
Quote Originally Posted by Extra Spell
You learn an additional spell.
Prerequisite: Caster level 3rd.

Benefit: You learn one additional spell at any level up to one lower than the highest level of spell you can currently cast. Thus, a 4th-level sorcerer (maximum spell level 2nd) gains a new 0-level or 1st-level spell known with which to expand her repertoire. For classes such as wizard that have more options for learning spells, Extra Spell is generally used to learn a specific spell that the character lacks access to and would be unable to research.
I'd rather not get involved in the Extra spell discussion, but I'll bold the interesting stuff.