Stealth
This is the ability to hide and to move silently. A successful roll lets you conceal yourself anywhere except in a totally bare room, or move so quietly that nobody will hear you, or follow someone without being noticed. (To follow someone through a crowd, use Shadowing.)
If someone is specifically on the alert for intruders, the GM will roll a Quick Contest between your Stealth and the sentinel's Perception. You can also use this skill to stalk game. A successful roll (and about 30 minutes) gets you within 30 yards of most animals. Another roll, at -5, gets you within 15 yards.
Modifiers: A penalty equal to your encumbrance level. -5 to hide in an area without "natural" hiding places, or +3 or more if there are many hiding places. -5 to move silently if you are moving faster than Move 1. -5 to fool those with Discriminatory Smell (e.g., dogs).