The art of escaping detection.
Use Infiltration whenever you need to physically hide or move with stealth to avoid someone sensing you, whether you are hiding behind a tree, sneaking past a guard, or blending into a crowd. Infiltration can also be used to follow people (shadowing) without them detecting you. Infiltration is an Opposed Test against the Perception of whomever you are hiding from. The gamemaster may wish to roll such tests in secret so the player does not know whether they have succeeded or failed.
Example (optional) specializations include Blending In, Hiding, Shadowing, Sneaking.