About Magic Use
As some of you may or may not know, in Ravenloft magic doesn't always work the way it normally should.
With that said, I'm borrowing a rule from another game in regards to spell casters:
●Spell Points = Intelligence + Level
The number generated (your spell points) is the number of times a character can cast spells before resting/praying/etc. So, for example, a 4th level spellcaster with a 14 intelligence can cast a total of 18 spells before needing to rest and relearn. You still memorize only the spells you know but can cast any multiple times, up to your spell point total.