Psychic Focus (Key, trained only)
This skill reflects those people who work to develop their mental powers to recognize a level of energy flow not normally thought to be actually present. This is not a magic ability, but reflects the use of one's own 'inner' perception to see what others do not. DMs should recognize that what someone with this ability claims to 'sense' is nonsense to others who probably do not even allow such eminations to exist (or cannot understand how one can detect them even if they do allow the possibility of them existing).
This skill comes from the Call of Cthulhu book, and was brought into the game in a development of a feat based psionic system (instead of presenting it as just another form of magic). While the system is still in development, some feats have been given to monsters (see the category link below) that enabled a strange type of encounter. Exactly how this skill is used is determined by associated feats, and it depends on those feats how, or if, this skill can be opposed.
Taking '10' or '20' may or may not be allowed with this skill, depending upon the feat being worked. Sometimes it does help to pause, and other times a 'cost' or 'risk' of failure is present. The ruling of the DM may also be necessary.
Retries are often allowed with this skill, although again it must be stated that it depends on which feat is being applied.
Considering that this skill reflects training one's mental skills, no special equipment is necessary for working this skill.