Sense Observation

Area 
Alerts the caster if someone or something spies or scries upon the subject area, by means magical or otherwise. A Quick Contest is rolled between the spy’s IQ or the effective skill of the Information spell’s caster (Trace, Seeker, Crystal Ball, any of the “Sense” spells . . .) and the effective skill of the Sense Observation spell’s caster; if the caster wins, he becomes aware that the subject area is being observed. A critical success (on the Contest) might give the caster an idea of who or what is doing the scrying or spying. 
If the caster then tries to seek out the spy, the margin of success of the Sense Observation contest can be added as a bonus to the Seeker roll, up to a maximum of +5 (effectively neutralizing the -5 penalty for having nothing associated with the person sought). Another possible course of action is to Counterspell the scrying spell; distance penalties do not apply, but the -5 penalty for absent subject does. 
Sense Observation can also be cast on a being; in that case, the caster can choose to have the spell alert the subject instead when eavesdropping is detected.

Duration: 1 hour. 
Base cost: 1 to cast. Half that to maintain. When cast on a being, the cost is 3. 
Time to cast: 5 seconds. 
Prerequisite: Sense Danger or Scryguard.

Item

• (a) Wand, staff, or jewelry.  
  Energy cost to create: 300.
• (b) Jewelry or clothing. Always on. Only affects the wearer.  
  Energy cost to create: 1,500.