"I sense something. A presence I've not felt since... ."—Darth Vader Star Wars "Episode IV: A New Hope"
A sub-trope of Psychic Powers in which they're used by a psychic character, usually but not always a telepath, to detect the presence of other people. The scope and range of this detection can be varied; from sensing the mind of a guard around the corner to Professor X being able to detect the presence of every mutant on the planet. Sometimes the power is tied to the detection of a mind; machines can't be detected by the psychic (crewed vehicles can), and Psychic Static and the Psychic Block Defense can be employed against it. This may or may not lead to being detected because of the defense.
Sometimes, the detection is limited to other psychics only.
Appears in as many media as do the telepaths providing it, though like them, it's generally restricted to Speculative Fiction and Superhero genres. It's especially common in Video Games and Tabletop Games. In film, TV, comics and animated media, use of this power will involve the Pstandard Psychic Pstance and high effort or contest with someone or something blocking your telepathic radar sweep can result in a Psychic Nosebleed. It's also common to see this represented in Film and Television with the searching psychic's eyes overlaid over the sought-after characters hiding place.
Sub-trope of Psychic Powers, closely related to Telepathy. May also invoke a touch of Sensor Suspense. Compare Supernatural Sensitivity, for when a Psychic Power is used to detect the use of other powers and contrast Spider Sense, for a much less focused and instinctual version.
- The Boys: Member of the super team Payback, Mindroid, can use his telepathy to detect the presence of another person in an are at least the size of a building. He can't precisely define an exact location, only whether or not someone's in the room or not and what their surface thoughts are.
- In an issue of Chuck Dixon's Team 7, a Russian telepath tries to use this to track them through the Cambodian jungle. It doesn't work, due to a "greater power." She gets a Psychic Nosebleed for her trouble.
- All of the telepaths on the X-Men (Professor X, Jean Grey/Phoenix, Cable, Psylocke, etc.) have displayed this from time to time, though usually only when the plot calls for it. Other times, they seem oblivious to people hiding right behind a door. Professor X and Jean Grey can be seen doing this together in X-Men Forever #7 while trying to track Fabian Cortez.
- Martian Manhunter can pinpoint individuals from miles away, though he often needs to dramatically fly into space in order to do so (presumably so he doesn't hear everyone else's thoughts).
- Serenity: River's psychic powers let her detect the incoming Reaver ship as it's descending through the atmosphere.
- Star Wars: As per the above quote, Jedi and Sith can sense the presence of other Force users; picking up a single other practitioner even amidst the myriad of minds on the Death Star.
- X-Men: Charles Xavier, through the use of Cerebro, is able to track the location of individuals precisely and can sense the locations of individuals.
- X 2 X Men United: Cerebro allows Xavier to simultaneously sense the locations of every person on the planet. Of course, the concentration required for this would kill them.
- Dracula: This goes both ways with the link between Mina and the Count. He can use it to spy on and know the movements of the heroes, but they can do likewise if they place Mina into a hypnotic trance; so she can sense the Count and his surroundings and roughly how far away he is.
- Oddly, Futuretrack Five's psycho-radar is not powered by a telepath. It's wholly mechanical, but it still works by detecting the presence of thoughts. Paramils are generally scanning for extremes of rage or despair, and particularly home in on the suicidal. It's demonstrated that it can be played with; a favourite pastime of Est children is thinking 'angry thoughts' when a psycopter flies over and then immediately thinking really bland thoughts, just to annoy the Paramils.
- In The Sharing Knife, a lot. Groundsense can detect any life.
- Sholan Alliance: Most of the main cast, who're almost all telepaths or some stripe, have used their telepathy to detect the presence of others at some point during the series.
- Command Performance, a 1952 short story by Walter M. Miller, Jnr., featured a young woman discovering she was a telepath and also that there was at least one other telepath out there; when she psychically sensed him in the street near her back garden. He'd already sensed her and had come to investigate.
- In the Necroscope novels people who have this "Talent" are called spotters, and are rarer even than regular Talents.
- Angel: In early seasons the evil law firm Wolfram & Hart uses psychics specifically to scan if a vampire has entered their building.
- Blakes Seven: Cally, the Auron telepath in the Liberator crew can detect the presence of other minds. It's how she sneaks up on Blake in an early episode.
- Firefly: River's psychic powers let her detect the presence of Reavers aboard a hulk drifting past Serenity and also pick up on the proximity of the blue-handed Alliance agents.
- Heroes: Matt Parkman can detect people he can't see by hearing their thoughts. In the first episode we meet him in, he uses this to find a little girl who's hiding from a murderer.
- Red Dwarf: During the episode "Quarantine," both Lanstrom and Rimmer, under the effects of the Holovirus, are able to home in on the location of the rest of the crew by sensing their thoughts.
- Highlander: Immortals can sense when another Immortal is around.
- The Detect power could be defined as detecting life in general, or specific kinds of life in particular (minds, aliens, humans or whatever).
- The Mind Scan ability could be used to detect life in an area, though it was normally used to find specific creatures.
- D 20 Modern: Telepaths have the psionic ability Detect Thoughts. The longer the telepath concentrates, the greater the area he can scan for other minds and the clearer the number of minds is. This power can be blocked by a sufficiently thick inorganic barrier.
- Dungeons and Dragons.
- Early editions had the Detect Life cleric spell, which could detect living creatures at a distance, and even through solid non-metal barriers.
- 2nd Edition introduced the psionic ability Life Detection, which allowed the user to detect the presence of living, thinking creatures within a limited area.
- Space Hulk: 1st Edition had a power, Scan in the game's Temporal deck, which allowed Librarians to identify Genestealer blips. This was later adapted into spin-off Space Crusade and its successor Advanced Space Crusade via articles in White Dwarf.
- West End Games Star Wars RPG gave Force users two powers to use for this trope Life Sense and Life Web. The former allowed them to sense the presence of a specific person and the latter allowed them to search for the presence of specific species.
- Traveller. The Telepathy psionic ability allowed the user to perform Life Detection. This involved detecting the minds of creatures in the area, including the number and type of minds present (animal, human, alien). It could be set to ignore unimportant animals and bacteria.
- Vampire: The Masquerade: High-level Auspex powers Omniscience (level 8) and Master Of The Dom (level 9) allowed a vampire to, respectively, detect the personalities and identities of individuals within an immediate radius (larger area based on more successes when rolling) and to detect the presence and activity of most people and animals in a regional area.
- Command & Conquer: Red Alert: Has the Psychic Sensor: which allows the detection of enemy units outside of Line of Sight and the prediction of their movements. Also the Psychic Radar which psychically revealed sections of the battlefield.
- Nethack: Telepathic characters can see the position of monsters even when physically blinded.
- Sins of a Solar Empire: the Advent research tree provides players with Forewarning and Acute Premonitions; allowing Advent telepaths to detect hostile fleets bound for the player's territory from increasing numbers of hyperspace jumps distance.
- Star Trek Online: Telepaths allow for the detection of cloaked vessels and units.