Clairvoyance (Summoner Spell)
Clairvoyance was a 'targeted' Summoner spell. It is mainly used for scouting, aiming skills, avoiding enemy ganks and setting up ganks of your own. It can't detect invisible units, but it can see into brush. Unlike wards, Clairvoyance does not need to be "placed" into a specific patch of brush, but instead reveals all of the map within its range.