Change up and add new failure effects of spellbook reading:

• Any failure confuses you instead of paralyzing.
• The level 5+ confusion effect seems quite tame in comparison to the other effects, so replace it with paralysis.
• New effect: book tries to eat you
• New effect: level drain
• Spell enters your head automatically, but erases your knowledge of one/all of your other spells. (This could be quite annoying and may be better off as an Evil Patch Idea.)
• New effect (possible in combination with other effects, and for any book): book curses

Books no longer have a 1/3 chance of disintegrating when failing to read them; instead, a cursed book will always disintegrate.