Sorcery in Heroes 4: effect by level and who learns it

Basic Sorcery

Basic Sorcery increases the hero’s spell damage (with all magic types) by 20%.

Advanced Sorcery increases the hero’s spell damage (with all magic types) by 40%.

Expert Sorcery increases the hero’s spell damage (with all magic types) by 60%.

Master Sorcery increases the hero’s spell damage (with all magic types) by 80%.

Grandmaster Sorcery increases the hero’s spell damage (with all magic types) by 100%.