Perception
Details
Perception determines your character's overall awareness and effectiveness with ranged weapons. It also affects your character's chance to detect hidden passages, objects or stealthed creatures and NPCs. It does not increase your vision or visible range. Perception does not directly affect your chance to hit, but rather increases your ranged weapon skills, which in turn increases your chance to hit with ranged weapons. Melee weapon hit rate is unchanged but increased with melee skill (through strength or dexterity). No items require perception to be used or equipped.
High perception score is important for characters who wish to use ranged weapons or find traps, stealthed enemies and secrets.
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Directly affected skills |
Other effects |
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Related feats
See Category:Perception feats.
- Snooping increases perception by 3 for the purposes of finding secrets.
- Increased Perception veteran feat increases it by 2.
Related items
Headwear
Adaptive Goggles (+1 Perception on equip)
Metal Helmets (-1 Perception on equip)
Aegis Sec-trooper Helmet E (-1 Perception on equip)
Praetorian Lawgiver (-1 Perception on equip)
Gas Mask (-2 Perception on equip)
Suit
Tchortist Noble Robe (-1 Perception on equip)
Tchortist Rassophore Armor (-1 Perception on equip)
Biohazard Suit (-2 Perception on equip)
Fire Proximity Suit (-2 Perception on equip)
Robe (-2 Perception on equip)
Tchortist Robe (-2 Perception on equip)
Food
All-in (temporarily +3 all base abilities)
Mushroom Salad (temporary +1 Perception)
Junkyard Surprise (temporary random base ability effect, can only decrease Perception)
Clean Deal (temporary -1 Perception)
Mushroom Brew (temporary -2 Perception)
Kzozel E (temporary -2 Perception)
White Dude (temporarily -2 Perception)
Drugs
Third Eye E (temporary +3 Perception for the purpose of finding secrets)
Bioluminous Marsh Honey E (temporary +2 Perception)
Supersoldier Drug (temporary +2 Perception)
The Juice (temporary +1 Perception)
Perception checks
Discovering secret areas is based on Perception score alone, unlike detecting traps and stealthed characters, which is based on Detection. Discovering some secrets requires prior knowledge instead of Perception score.
In addition to secrets, Underrail: Expedition expansion added visible in-world Perception checks similar to Strength, Dexterity and Agility checks.
Base game
- This list is incomplete; you can help by expanding it.
| Location | Secret | Requirement | Details |
|---|---|---|---|
| Lower Caves, South Gate Outposts, Area South outposts, inside NW outpost (Forlornstations1.png) | Trapdoor | 6 Perception | connects the two south outposts |
| Lower Caves, South Gate Outposts, Area South outposts, inside NE outpost (Forlornstations1.png) | Trapdoor | 6 Perception | connects the two south outposts |
| Lower Caves, South Gate Outposts, Area East outpost, inside the outpost (ForlornStations4.png) | Trapdoor | 7 Perception | connects east and northwest outposts |
| Lower Caves, South Gate Outposts, Area East outpost, northeast tunnels (ForlornStations4.png) | Trapdoor | 8 Perception | connects east and northwest outposts |
| Under-passages area 1, near SGS (lup-a1.png) | Door | 7 Perception | secret room along east wall, Strange Comm Device oddity |
| Lower Underrail, GMS compound level 1 (GammaCompound1.png) | Safe | 7 Perception | secret safe in room near southwest corner |
| Lower Underrail, GMS compound level 2 (GammaCompound2.png) | Secret passage | 7 Perception | secret room along east wall, Old Data Medium oddity |
| Lower Underrail, GMS compound level 3 (GammaCompound3.png) | First aid box | ? Perception | SW room, hidden under couch, medicine including an advanced health hypo |
| Lower Caves, east from GMS compound level 3 (cv12.png) | Secret crawlspace | 8 Perception | leads to the back entrance of the raider base |
| Lower Caves, raider base | Adrenaline shot | ? Perception | under Page's bed |
| Lower Caves between Mushroom Cove and Junkyard (jyt1.png) | Underwater rock bridge | 8 Perception | leads to a small island |
| Lower Caves, Siphoner Pools, northeast (jyt3.png) | Underwater rock bridge | 8 Perception | leads to the northeast corner of the cave |
| Lower Caves, Water Treatment Facility | Plasma cell | ? Perception | under a table in the power room |
| Lower Caves, Water Treatment Facility | Shotgun shells | ? Perception | on top of a locker in the SE room on the upper level |
| Lower Caves, Water Treatment Facility | First-aid kit | ? Perception | in the SE room on the lower level, has antidotes |
| Lower Caves, Water Treatment Facility | Deathstalker corpse with oddity | ? Perception | in a secret compartment in the ventilation system |
| Lower Caves, Water Treatment Facility | Hidden vent shaft | ? Perception | along north wall on the lower level, leads to secluded room with loot |
| Silent Isle, southeast (si1.png) | Underwater rock bridge | 7 Perception | leads to a small island with a corpse |
| Junkyard, Security control room of Depot A east area (ojy2.png) | Secret door | 10 perception | shortcut bypassing the turrets |
| Lower Underrail area 6, Lunatic camp (lu-a6.png) | Hidden stash | 8 Perception | secret footlocker near rock pile |
| Upper Caves, south of Milton's camp (lux-a10.png) | Underwater rock bridge | 7 Perception | shortcut between the north and south bank of the river |
| Upper Caves, ironhead camp, north of the Bunker (Lux-b16.png) | Hidden stash | ? Perception | NW corner of map, through the backside of the camp, a jumping bean and tabi boots |
| Upper Caves, Synesthete/Formedicator camp, under the Oculus | Hidden stash | ? Perception | in the rock next to the Synesthete, 293 charons |
| Upper Caves, misty river north of Hecate caves entrance | Hidden box | ? Perception | contains a luxury item |
| Upper Caves, Lost Vault entrance (Lux-b9.png) | Hidden ventilation shaft | ? Perception | leads into the shack behind the trader |
| Upper Caves, Lost Vault interior | Hidden first-aid box | ? Perception | 2 antidotes and a health hypo |
| Upper Caves, Lost Vault interior | Hidden footlocker | ? Perception | in room along north wall, electronic component(s) |
| Upper Caves, Lost Vault interior | Hidden bag | ? Perception | in room along west wall, advanced repair kits & a lighter |
| Lower Caves, south of Crossroad Caves (cv2.png) | Trapdoor | 8 Perception | connects southwest and southeast corner, locked box with random psionic mentor |
| Lower Caves, south of Crossroad Caves (cv2.png) | Underwater rock bridge | 7 Perception | shortcut bypassing siphoners |
| Lower Caves, south of Camp Hathor (cv19.png) | Underwater rock bridge | 7 Perception | shortcut bypassing rathound nest |
| Lower Caves, Rathound King Lair (rkl2.png) | Door | Quest trigger | shortcut leading outside if you offer to kidnap Sarine or negotiate a truce with Camp Hathor |
| Lower Caves, Rathound King Lair, outside (cv21.png) | Door | Quest trigger | shortcut leading to the lair if you offer to kidnap Sarine or negotiate a truce with Camp Hathor |
| Lower Underrail, Abandoned Warehouse (aw1-1.png) | Secret crawlspace | 7 Perception | secret ventilation shaft section with a footlocker and a rathound |
| Rail Crossing, behind bar (rc1.png) | Secret door | 7 Perception | leads to Deacon's shop |
| Rail Crossing, Buzzer's Shop's ventilation shafts (rc_shop 3.png) | Hidden Ventilation Shaft | 7 Perception | secret ventilation shaft section with Hardware Bug |
| Lower Underrail, The warehouse from Dude's vision (lu-b4.png) | Secret crawlspace | Quest trigger | leads to the lower level of the warehouse during Dude's quest |
| Free Drones Base, east room | Trapdoor | 11 Perception | can't be opened; handle breaks |
| Upper Caves, north from the Hanging Rat bar (lux-c2.png) | Hidden stash | 11 Perception | secret stash inside rock pillar (not visible on the linked map) |
| Foundry, Evelyn's home (fo3.png) | Trapdoor | 10 Perception | connects Evelyn's house and bunker |
| Foundry, Evelyn's home (fo3.png) | Secret crawlspace | Quest trigger | leads to Evelyn's bunker if a male player character has a drink with her |
| Lower Underrail, cave west of Foundry (lu-b22x.png) | Hidden stash | 10 Perception | secret stash inside rock pillar |
| Core City, utility section (Cc_utility.png) | Squeeze though gap in pipes (3 agi) | ? Perception | leads to Phreak's hideout |
| Core City, utility section steam area, NW corridor | Junk pile | ? Perception | mechanical components (probably randomized) |
| Core City, utility section electric coil area, SE room on 2nd floor | Bag | ? Perception | knife (probably randomized) |
| Core City, utility section east of steam console, through the door along the south wall | Plasma cell | ? Perception | hidden plasma cell |
| Core City, Drop Zone (cc15.png) | Secret door | Quest trigger or 6 Perception | leads to Bogdan's hideout, can be found with perception or by learning about it from Kupusije during Find Bogdan, or with perception after starting Sewers generator/Retrieve ICPD |
| Core City, inside one of Drop Zone buildings (cc5_1.png) | Trapdoor | 8 Perception | leads to the basement |
| Core City, north Core City Sewers (cc_s2.png) | Door | 8 Perception | leads to a secret room on the west side |
| Core City, northwest Core City Sewers (cc_s6 2.png) | Switch | Quest trigger | opens door to Acid Hunters' hideout during the Look for Cornell quest |
| Upper Underrail, east of Notus Living Block (up3x.png) | Trapdoor | 7 Perception | connects trapdoor and a Lunatic base |
| Upper Underrail, inside Panacea Lab (plb.png) | Switch | 8 Perception | opens door to the room in the northeast corner |
| Upper Underrail, northeast corner (Up7.png) | Ventilation Shaft | ? Perception | Connects inside of structure to outside, north of the barrel fire |
| Institute of Tchort, utility section, northeast corner (tch-util3.png) | Ventilation Shaft | 8 Perception | connects west wing and utility section |
| Institute of Tchort, west wing, in coil spider room (tch-ww2.png) | Ventilation Shaft | 7 Perception | connects west wing and utility section |
| Institute of Tchort, Harpocrates Station, north room (tch_met.png) | Secret crawlspace | Quest trigger | leads to the ventilation system during Track down Rassophore Nevil |
| Institute of Tchort, Upper Underrail Ventilation System (tch_mv1.png) | Secret crawlspace | 8 Perception | secret ventilation shaft section with a box |
| Institute of Tchort, Upper Underrail Ventilation System, southwest room (tch_mv1_2.png) | Secret trapdoor | 10 Perception | leads to hidden basement |
| Deep Caverns, lake, northeast bank (dc-lk.png) | Underwater rock bridge | 7 Perception | leads to a small island with hackable box |
| Deep Caverns, lake, southwest islet (dc-lk.png) | Sniper rifle | 10 Perception | reveals Black Arrow sniper rifle |
| Deep Caverns, Hollow Earth (dc-la2.png) | Secret crawlspace | 8 Perception | secret entrance to the small building on the east |
| Deep Caverns, checkpoint between Caerus and warehouses (dc-cp1.png) | Underwater rock bridge | 8 Perception | leads to the east bank of the lake |
| Deep Caverns, Warehouse Block 2, south toxic storage (dc-wh3.png) | Trapdoor | 8 Perception | leads to lower level, Electrokinetic Imprint mentor |
| Deep Caverns, Caerus Residential, northwest building, second floor (dc-res2 2.png) | Ventilation Shaft | 10 Perception | leads to a cavern with Gunter Vasilica, Pseudo-spatial Projection mentor, and Regenerative Mixture |
| Deep Caverns, Caerus Residential, west apartment (dc-res3.png) | Safe | 6 Perception | secret (empty) safe |
| Deep Caverns, Arke Power Station, utility section toxic storage (dc-pp_ut.png) | Trapdoor | 11 Perception | connects toxic storage and storage room, random psionic mentor |
| Deep Caverns, Arke Power Station, utility section storage room (dc-pp_ut.png) | Trapdoor | 10 Perception | connects toxic storage and storage room, random psionic mentor |
| Deep Caverns, Deep Mushroom Forest (dc-fs4.png) | Secret tunnel | 9 Perception | leads to the northwest corner and a skeleton |
Expedition
- This list is incomplete; you can help by expanding it.
| Location, Underrail | Secret | Requirement | Details |
|---|---|---|---|
| Abandoned Waterway Facility, east zone | Hidden stash in rock pillar | ? Perception | exceptionally high-quality mutated-dog leather |
| The Rig, room #2 | Note (The Rig) | 5 Perception | under the bed |
| Chancer's Bay, NE map | Hole through wall of shack | 10 Perception | biohazard boots, mutants |
| Isaac's River, northernmost map | Hidden stash | 10 Perception | stash in north wall of cave |
| Core City Docks, empty room next to Ray's shop | Vent in north wall | ? | leads into Ray's shop, dying burglar |
| Dude's House - Core City | Cracked floor panel/wall safe | ? | key to wall safe/the safe itself |
| Dude's House - Caves | Footlocker under bed | 9 Perception | psionic mentor |
| Grey Army Base, two rooms east of the rift | Secret trapdoor | 8 Perception | electronic components |
| Grey Army Base, 2nd floor | Wall safe | 9 Perception | secret safe in north wall of northwest room |
| Grey Army Base, 2nd floor | Secret crawlspace | 9 Perception | Connects northern and southern parts of the ventilation system |
- This list is incomplete; you can help by expanding it.
| Location, Black Sea | Secret | Requirement | Details |
|---|---|---|---|
| Black Sea (E4), north side of island | Entrance to cave | 11 Perception | entrance to pirate prison sewer, boss hermit crab |
| Siphoner Pools (Black Sea) | Underwater rock bridge | 7 Perception | leads to a lingula plant and a random treasure "crevice" |
| Siphoner Pools (Black Sea), west chamber | Buried box | 11 Perception | SGS credits, Charons, UN dollars |
| Black Sea (C8), hopper island cave, north wall, west side | Hidden stash | 9 Perception | secret stash in cave wall, quiver belt and special bolts |
| Black Sea (A10), Yngwar's cave island, hidden walkway in water on east side | Hidden stash | ? Perception | secret stash in cave wall, coagulation shot(s) and rusting acid chemical ammo |
| Mutie Refuge, crane room | Hidden vent shaft | 7 Perception | secret vent shaft through wall into crane room |
| West Storage Depot, lvl 3 by the elevator | Hidden vent shaft | 8 Perception | secret vent shaft to blocked room |
| Crimson Meadow Horticulture Center lower floor, west section, north side | Hidden vent shaft | 11 Perception | secret vent shaft through wall |
| Black Sea (I1), outside the Health Center, SE corner | Hidden hole through wall | 10 Perception | secret passage to hidden room |
| Black Sea (I2), tower north of Health Center, 2nd floor | Hidden corpse | 9 Perception | corpse with loot (can be looted without detection) |
| Nexus of Technology, level 1, SE room | Hidden wall safe | 9 Perception | loot |
| Port Crag, east building | Hidden pipe tunnel | 9 Perception | Crawl through to west building, 2nd floor (agility 8; it is from the other direction) |
| Fetid Marsh, east side of K5/west side of L5 | Hidden map exit(s) | 7 Perception | secret camp with Signed Arena Ticket Oddity and Slimy Tablet Computer |
| Fetid Marsh, SW corner of K4 | Hidden pool jumps | 12 Perception | secret platforms for easier jumping across leper pool |
| Map M7 (two maps east of the Nexus), NW corner | Hidden passages | 9 Perception | secret passages to/from hidden room, shortcut past creepers |
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