For wizards, knowledge is power

The chance of successfully casting a spell from a scroll or a book depends on two factors: the caster's Intelligence bonus and their Arcane Casting skill level. Let's take a closer look at the numbers.

A level 1 apprentice with a +2 Intelligence modifier and Basic level in Arcane Casting will have a 40% chance to fail, with a 5% chance of backfire. This means that even their ability to cast simple spells is unreliable. The chance to cast a 9th level spell is higher, with only a 20% chance to succeed and a 45% chance of backfire.

A Wizard who dedicates themselves to improving their spellcasting skill can reach the Master level in Arcane Casting as early as level 3. With a +2 Intelligence, this means that casting a level 1 spell has a 94% chance to succeed (with around a 0.01% chance to backfire), and a level 9 spell has a 51% chance to succeed (with around a 9% chance to backfire).

While gaining Wizard levels has its perks (increased spell power, spells known by heart, feats, and increased Intelligence), the crucial factor for the reliability of spellcasting is the Arcane Casting skill level, which can be optimized early in the game. Therefore, a Wizard is only as strong and versatile as their spell repertoire. Acquiring spells is not an easy task. The Wizard needs to find copies, bargain, and collect spells over time. The acquisition of truly powerful spells requires extensive research and questing.

If you aspire to be a strong Wizard, you can't simply follow around a bunch of goons in the dungeon. You need to actively pursue knowledge and engage in your own quest for mastery.