Assassins, bards, and sorcerers cast arcane spells, but they do not have spellbooks and do not prepare their spells. An assassin’s, bard’s, or sorcerer’s class level limits the number of spells he can cast (see these class descriptions).
An assassin’s high Intelligence score might allow him to cast a few extra spells. The same is valid for bards’ and sorcerers’ Charisma.
An assassin must have an Intelligence score of at least 10 + a spell’s level to cast the spell. The same is valid taking Charisma for bards and sorcerers.
Daily Readying of Spells: Each day, assassins, bards, and sorcerers must focus their minds on the task of casting their spells.
An assassin, bard, or sorcerer needs 8 hours of rest (just like a wizard), after which he spends 15 minutes concentrating. (A bard must sing, recite, or play an instrument of some kind while concentrating.)
During this period, the assassin, bard, or sorcerer readies his mind to cast his daily allotment of spells. Without such a period to refresh himself, the character does not regain the spell slots he used up the day before.
Recent Casting Limit: As with wizards, any spells cast within the last 8 hours count against the assassin’s, bard’s, or sorcerer’s daily limit.
Adding Spells to an Assassin’s, Bard’s, or Sorcerer’s Repertoire: An assassin, bard, or sorcerer gains spells each time he attains a new level in his class and never gains spells any other way.
When your character gains a new level, consult the spells known table to learn how many spells from the appropriate spell list he now knows. With permission, assassins, bards, and sorcerers can also select the spells they gain from new and unusual spells that they have gained some understanding of.