Mark of Shadow [Dragonmark]

Heroic Tier
Benefit: Whenever you make an attack and miss every target while hidden, you remain hidden.
Whenever you make an attack and miss every target while invisible, you remain invisible.
You can master and perform rituals in the deception and scrying categories and the Knock, Masking Shroud, Secret Page, and Shadow Walk rituals as if you had the Ritual Caster feat.

Published in Eberron Player's Guide, page(s) 91.