"If I were you, I'd grow eyes in the back of my head."
-- The Shawshank Redemption
360° Vision is a physical, exotic advantage described in Basic Set, p. 34. It has the special limitation Easy to Hit. It is referenced in GURPS Powers™, pp. 19 and 39, where two special enhancements are given, Panoptic 1 and Panoptic 2.
Sapient Building in GURPS Biotech are given 360 vision
The Chimera in GURPS Fantasy p. 51 are given 360 vision.
Coleopteran in GURPS Dungeon Fantasy 3 are given 360 vision
Swamp Monster in Horror is given 360 Vision p. 64
The Arendians in Horror are given 360 Vision p. 85
Myrmidons in Horror are given 360 Vision p. 160
Medical Bush Robot in GURPS Ultra-Tech are given 360 vision p. 203
Unknowable Things in Pyramid 3-72 Alternate Dungeons are given 360 Vision p. 25
- Acid Spiders are given 360° Vision in Dungeon Fantasy 2: Dungeons™, p. 21.
- Electric Jelly is given 360 Vision in GURPS Dungeon Fantasy Monsters 1, p.13
- Tiberius' Wolves are given 360 Vision in Pyramid #3-27 Monsters in Space, p. 9
- Aetherial Skimmers are given 360 vision in Pyramid #3-27 Monsters in Space p. 10
- Slimeballs are given 360 Vision in Pyramid #3-32 Fears of Days Past p. 9
- Xiangliu (Nine-Headed Snake) is given 360 Vision in Pyramid #3-70 Fourth Edition Festival p. 30
- Giant Ants in Pyramid 3-73 Monster Hunters II are given 360 Vision p. 15
- Pscropion is given 360 Vision in Pyramid #3-76 Dungeon Fantasy IV p. 10
- Hungry Room is given 360 Vision in Pyramid #3-76 Dungeon Fantasy IV p. 22
- The One Who Eats is given 360 Vision in Pyramid #3-80 Fantasy Threats p. 14
- Astral Spider are given 360 Vision in Pyramid #3-80 Fantasy Threats p. 33
- Chaos Ooze are given 360 Vision in Pyramid #3-80 Fantasy Threats p. 34
- On its visibility to others, and how Panoptic 1 affects that 
- On its use to build a character with no facing 
Explicitly Allowed Modifiers Edit
The following are general modifiers that are ones through mention or example are confirmed to be allowed on this advantage: