I have been pondering the question of ways to evade notice while astrally projecting, and I read this line in the BBB, p.171:

That's how I do it.

An Astral Patrolling tets really isn't a Preception test though, is it? I don't think Line of Sight is even considered with it, which is a major factor in Perception tests. However, I think the two are somehow connected. Success on an Astral Patrol test alerts the patrolling spirit to an intruder, but doesn't specify where the intrusion took place. Depending on the patrolling spirits command, it may seek out the intruder thus requiring an Astral Perception test (perhaps modified by some of the same affects as Astral Patrolling), or it may more to alert security forces who would also be required to spot the induding astral form.

Yeah but against regular people watching, it works quite well. They are just pointing out that the sight component of astral perception works just like normal sight in that regard. It is a free action to notice someone standing across the street unless they are trying to hide from you.

I tend to think of astral patrol tests as a role to determine wether you encounter an astral protector. If you do then you still have the possibility that it dose not notice you, use stelth skill for that test.

Edward

The Stealth Skill is certainly usable while Astrally Projecting (or even Perceiving). I believe you can even have Astral as a Specialization of the Stealth Skill.