With scent, you automatically detect the presence of invisible foes without needing a rather high Spot or Listen check, which is more than no actual benefit unless your Spot and Listen skills are 20+. Plus you can track.dcollins said:(5) Is counter to how I personally ruled in one fight with creatures using Scent against a Shadowdancer trying to sneak attack (which was controversial with the player in question). It seems to weaken Scent quite a bit if the "detection" of invisible creatures apparently gives no actual benefit (other than opening the door for pinpointing, which doesn't really allow even a single attack, since finding direction takes a standard action).