Adept's Set

# of Pieces Worn	Spell(s)	Bonus Effect(s)
1	None	None
2	Novice Artifex's Item Aptitude Novice Enchanter's Creature Aptitude Novice Theurge's Life Magic Aptitude Novice Warlock's War Magic Aptitude	+3 to Item Enchantment +3 to Creature Enchantment +3 to Life Magic +3 to War Magic
3	Apprentice Artifex's Item Aptitude Apprentice Enchanter's Creature Aptitude Apprentice Theurge's Life Magic Aptitude Apprentice Warlock's War Magic Aptitude	+5 to Item Enchantment +5 to Creature Enchantment +5 to Life Magic +5 to War Magic
4	Journeyman Artifex's Item Aptitude Journeyman Enchanter's Creature Aptitude Journeyman Theurge's Life Magic Aptitude Journeyman Warlock's War Magic Aptitude Novice Negator's Magic Resistance	+10 to Item Enchantment +10 to Creature Enchantment +10 to Life Magic +10 to War Magic +3 to Magic Defense
5	Master Artifex's Item Aptitude Master Enchanter's Creature Aptitude Master Theurge's Life Magic Aptitude Master Warlock's War Magic Aptitude Apprentice Negator's Magic Resistance	+20 to Item Enchantment +20 to Creature Enchantment +20 to Life Magic +20 to War Magic +5 to Magic Defense
6	No More Additional Bonuses

Notes

Bug #1: With 2 or 3 pieces, the set casts Artifex's Item Aptitude twice, instead of Enchanter's Creature Aptitude.
Bug #2: With 5 pieces, the set says it casts Novice Warlock's War Magic Aptitude instead of Master Warlock's War Magic Aptitude, however you still retain the +20 bonus.