Look on page 58. There is a box that says "Spells Vs. DEF". All of those Bolt/attack spells are "Vs. DEF" (check their attributes...)
That sidebar/box explains how to resolve them...
But to recap, it is simple...
1) Roll dice to cast spell (remember this result, it will be used multiple times) -- result == dice roll + spellcasting skill bonus -- IF result is equal to or greater than CTN, then spell is cast correctly, go to #2. If result is less than CTN, then spell fails, end process.
2) If spell was cast correctly, compare result of casting roll to foe's DEF. If equal to or greater than foe's DEF, then attack hit, and damage is figured the same as any other attack (i.e. Base Damage + Scaled Damage of +1 hit for every point result was over foe's DEF). If the result was less than foe's DEF, the attack missed..
