Auspex 4 enables a character to try and detect whether there are other minds nearby – possibly hidden. It requires a Perception + Awareness roll, resisted by the target’s Manipulation + Subterfuge, to determine where the thoughts are coming from.
Disguising one’s mental presence in another’s mind is a Man + Sub roll, resisted by the target’s Per + Awa.
Auspex 5 is now a Perception + Awareness roll.
Perception + Awareness is also the roll used to detect the presence of an astrally projected being nearby – difficulty 8.
Seeing the Unseen
Using Auspex to pierce Obfuscate and/or Chimerstry is a Preception + Awareness roll, contested by Manipulation + Subterfuge.