Detection may be blocked by trees, rocks or buildings.
Power level also affects quantity of information revealed about enemies.
thumb|An example of Enemy Surveillance
In the example on the right, we can see that the archer is of difficulty Impossible and moving south east.
On the third time, the archer was obstructed by an obstacle, such as a rock or tree, which caused no tracks to be found.
Enemy Surveillance can be used while Camouflage is active but not during Stalker Surroundings.
Documented changes
*Version 1.0.6 : Casting time and mana consumption reduced in all levels. Tactical information is now received in every level.
*Version 0.9.33 : Spell description fixed. Animation fixed.