Spell critical

Spell critical
Unlike weapon critical, your base chance to make spell critical is 0%. Unless you have some sort of spell critical equipment or enhancement (to your critical chance), you never score a spell critical. Your base critical multiplier is x1.5. The damage number on the screen is shown with larger font when spell critical is scored.

Example: Your Niac's Cold Ray would do 40 points of cold damage on a failed reflex save. With septer in your hand, you have 6% chance to do 60 points instead on a failed save.

Critical hits dealt by the spell are rolled each time a damage effect is applied rather than only when the spell is cast. For Fireball, spell critical is rolled and applied per enemy within the area of effect. For Magic Missile, spell critical is rolled and applied per tick of damage.

Spell criticals are applied only on straight spell damage to your enemy HP (or healing on your ally). Your Jump buff doesn't crit and give greater bonus to your skill. Your Energy Drain doesn't crit and give 6 negative levels instead of 4.

Spell Critical Chance enhancements
Spellcasting classes can take following to increase their spell critical chance. Tier I gives +4%, after II +1% each, up to 9% at tier VI.
 * Wizard/Sorcerer
 * Corrosive Spellcasting I-VI
 * Glacial Spellcasting I-VI
 * Charged Spellcasting I-VI
 * Combustive Spellcasting I-VI
 * Kinetic Spellcasting I-VI
 * Reconstructive Spellcasting I-VI
 * Cleric/Favored Soul
 * Bard
 * Bard

Spell Critical Damage enhancements
Spellcasting classes can also take following to increase their spell critical multiplier. Tier I gives +0.25, after II +0.10 each, up to +0.75 at tier VI, giving a total bonus of 1.25 (0.50 base + 0.75). Hence with Tier VI you would crit for x2.25 damage with the corresponding spells.
 * Wizard/Sorcerer
 * Deadly Acid I-VI
 * Deadly Ice I-VI
 * Deadly Shocks I-VI
 * Deadly Flame I-VI
 * Deadly Kinetics I-VI
 * Mighty Reconstruction I-VI
 * Cleric/Favored Soul
 * Bard
 * Bard