Preparing Wizard Spells
A wizard’s level limits the number of spells she can prepare and cast. Her high Intelligence score might allow her to prepare a few extra spells. She can prepare the same spell more than once, but each preparation counts as one spell toward her daily limit. To prepare a spell the wizard must have an Intelligence score of at least 10 + the spell’s level.
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Spell Selection and Preparation
Until she prepares spells from her spellbook, the only spells a wizard has available to cast are the ones that she already had prepared from the previous day and has not yet used. During the study period, she chooses which spells to prepare. If a wizard already has spells prepared (from the previous day) that she has not cast, she can abandon some or all of them to make room for new spells.
When preparing spells for the day, a wizard can leave some of these spell slots open. Later during that day, she can repeat the preparation process as often as she likes, time and circumstances permitting. During these extra sessions of preparation, the wizard can fill these unused spell slots. She cannot, however, abandon a previously prepared spell to replace it with another one or fill a slot that is empty because she has cast a spell in the meantime. That sort of preparation requires a mind fresh from rest. Like the first session of the day, this preparation takes at least 15 minutes, and it takes longer if the wizard prepares more than one-quarter of her spells.
Spell Slots
The various character class tables show how many spells of each level a character can cast per day. These openings for daily spells are called spell slots. A spellcaster always has the option to fill a higher-level spell slot with a lower-level spell. A spellcaster who lacks a high enough ability score to cast spells that would otherwise be his or her due still gets the slots but must fill them with spells of lower level.
