From Lineage 2 Encyclopaedia

Properties

Robe Mastery
Increases P. Def. by 1.7 when equipped with a robe.
Class	Dark Wizard
Type	passive
Attribute	-
Recast time	0 s
Cast time	0 s
Cast range	0
Classes with same skill	Wizard, Sorcerer, Necromancer, Warlock, Elven Wizard, Spellsinger, Elemental Summoner, Dark Wizard, Spellhowler, Phantom Summoner, Archmage, Soultaker, Arcana Lord, Mystic Muse, Elemental Master, Storm Screamer, Spectral Master

Skill Upgrade

Lvl. to Learn	Skill Lvl.	Description	MP Consume	HP Consume	SP
20	1	Increases P. Def. by 1.7 when equipped with a robe.	0	0	4
20	2	Increases P. Def. by 2.7 when equipped with a robe.	0	0	4
25	3	Increases P. Def. by 4.3 when equipped with a robe.	0	0	6
25	4	Increases P. Def. by 5.4 when equipped with a robe.	0	0	6
30	5	Increases P. Def. by 7.2 when equipped with a robe.	0	0	9
30	6	Increases P. Def. by 8.5 when equipped with a robe.	0	0	9
35	7	Increases P. Def. by 10.6 when equipped with a robe.	0	0	11
35	8	Increases P. Def. by 12.1 when equipped with a robe.	0	0	11