Anomaly

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This article is for the PC version of Stellaris only.

Exploration

FTL

Anomaly

Precursors and Archaeology

Unique systems

L-Cluster

An anomaly is represented by survey readings that deviate from what is normal. When a science ship surveys a celestial body it may identify an anomaly that needs further investigation. Anomalies have their own tab in the Situation Log.

When the investigation of an anomaly is complete, an event will pop up that can give various bonuses, such as research points, resources on a planet, or even a special project which requires further research investment to unlock benefits. Certain Ethics occasionally have additional options.

Each surveyed celestial body has a 5% chance of spawning an anomaly, which is increased by 0.5% for every surveyed planet with no anomaly before being reset. The Meticulous trait and Map The Stars edict also increase the chance of finding anomalies by 10%.

Level[edit]

To investigate an anomaly, a science ship with a scientist on board must be present at the celestial body where the anomaly is located. Investigating them takes time, which is determined by the level of the scientist minus the difficulty level of the anomaly. As such, anomalies of higher levels are often best left off until a skilled scientist can study them faster.

Level difference	Investigation days
+9 (Inconsequential)	20
+8 (Inconsequential)	24
+7 (Trivial)	30
+6 (Trivial)	35
+5 (Very Easy)	45
+4 (Very Easy)	55
+3 (Easy)	65
+2 (Easy)	80
+1 (Routine)	100
0 (Routine)	120

Level difference	Investigation days
-1 (Routine)	180
-2 (Challenging)	300
-3 (Challenging)	540
-4 (Hard)	720
-5 (Hard)	1080
-6 (Very Hard)	1440
-7 (Very Hard)	2160
-8 (Hellish)	2880
-9 (Hellish)	5760

Anomaly list[edit]

Each anomaly can only be found x times where x is the number of possible outcomes. Once a certain outcome of an anomaly has occurred, the same outcome cannot happen if the anomaly is discovered again.

Anomaly (single outcome)	Level	Rewards	Celestial body
Icy Plains	4		Arctic
Arid and Abandoned	6		Arid
Arid Wastes	3		Arid
Abandoned Station	3		Asteroid
Alien Machine	3		Asteroid
An Asteroid, Carved	3	event chain	Asteroid
Asteroid Collision	1		Asteroid
Astonishing Asteroids	6		Asteroid
Covered in Debris	3		Asteroid
Mind the Minerals	2		Asteroid
Orbital Speed Demon	4	event chain	Asteroid
Radiating Asteroid	7		Asteroid
Spacecraft Remains	4		Asteroid
Unknown Insides	3		Asteroid
A Curious Signal	2		Barren
On the Barren Plains	5	event chain	Barren
Peculiar Crater	7		Barren
Winking	5		Barren
Desolate Sands	1		Desert
Ice Lit	3		Frozen
Something Smells	2		Frozen
Minesweeper	2		Gaia
Paradise Anticipated	3		Gaia
Atmospheric Storms	1		Gas Giant
Cargo Pod	1		Gas Giant
Clouds Dance	1		Gas Giant
Gas Giant Ship	5		Gas Giant
Gas Giant Signal	5	event chain	Gas Giant
Ice Ice Giant	6		Gas Giant
Promising Moon	1		Gas Giant
Terminal Orbit	5		Gas Giant
Heated Rhythm	2		Molten
Drops in the Ocean	3		Ocean
Floating Value	3		Ocean
Kaleidoscopic	2		Ocean
The Winter of the Fallen	3		Tomb
Impossible Organism	6	event chain	Toxic
Pigment Poison	7		Toxic
Poison-coated	2		Toxic
Toxic Construction	8		Toxic
Toxicity	3		Toxic
Among the Vines and Trees	3		Tropical
Scurrying	4		Tropical
Tropical Oddities	3		Tropical
Wooden Hegemony	3		Tropical
Possible Inhabitants	3		Dry Planet
Parked	8		Any Habitable Planet
Planetary Scars	4		Any Habitable Planet
Rubiconian Shores	7	event chain	Any Habitable Planet
Signs of Ancient Life	3		Any Habitable Planet
Steamrolled	1		Any Habitable Planet
Ancient Shipyard	4		Any Uninhabitable Planet
Asteroid in Orbit	1		Any Uninhabitable Planet
Atmospheric Anomaly	3		Any Uninhabitable Planet
Doppler Effect	3	event chain	Any Uninhabitable Planet
Life Signs	2		Any Uninhabitable Planet
Monoliths	3		Any Uninhabitable Planet
Projecting	3		Any Uninhabitable Planet
Signs of Battle	4		Any Uninhabitable Planet
Solar Sailer	2		Any Uninhabitable Planet
Space Station	1		Any Uninhabitable Planet
Strange Mountain Formation	3		Any Uninhabitable Planet
Surface Beacon	1		Any Uninhabitable Planet
Surface Writing	2		Any Uninhabitable Planet
Unidentified Object	2		Any Uninhabitable Planet
Distress Signal	2		Any Planet
Playful Ruins	3		Any Planet
Improbable Orbit	5		Any Star
Light Phenomenon	3		Any Star

Anomaly (multiple outcomes)	Level	Outcomes	Celestial body
Asteroid Waves	1	4 (Trait granting: Biology)( and income)	Asteroid
Crashed Ship	3	2	Asteroid
Dimensional Disturbance	6	2	Asteroid
Docking Hatch	3	2	Asteroid
Dustbowl	1	3 (Gave Ion Thrusters Tech)	Asteroid
Energy Emissions	1	2	Asteroid
Mineral Cluster	3	4 (Trait granting: Carefree, Voidcraft, Statecraft)	Asteroid
Odd Readings	6	2	Asteroid
Unknown Origin	1	3	Asteroid
Looking Down	6	2	Barren
Strange Emissions	4	3	Barren
Buried in the Sand	4	2	Desert
Dunes	3	3	Desert
Cold Hard Potential	3	4	Frozen
Cold Wastes	2	2	Frozen
Aerostat Structures	1	2 ( income)	Gas Giant
Atmospheric Object	4	2	Gas Giant
Space Debris	1	2 (Trait granting: Maniacal)	Gas Giant
Signs of Former Habitation	1	2	Toxic
Continental Findings	1	3	Continental
Rainbow in the Dark	5	2	Black Hole
Spotty Greenery	4	2 (trait granting: Industry)	Wet Planet
A Lush Planet	4	4	Any Habitable Planet
Peculiar Patterns	3	3	Any Habitable Planet
What Hums in the Night	5	2	Any Habitable Planet
Massive Impact	2	2	Any Uninhabitable Planet
Tomb World	4	2	Any Uninhabitable Planet
Unusual Energy Readings	2	4 ( income)	Any Uninhabitable Planet
Weak Signal	2	2	Any Uninhabitable Planet

Distant Stars anomalies[edit]

Distant Stars anomalies have only one possible outcome.

Anomaly	Level	Reward	Celestial body	Requirements
Armed Vessel	3	50 Influence or special project to gain 90-250 Engineering Research	Asteroid	No empire discovered the same anomaly
Secret Heart	5	+1 Rare Crystals deposit	Asteroid
Unscannable Object	1	90-250 Physics Research +1 L-Gate Insight if an L-Gate was discovered	Asteroid
Waterless Canyons	1	+4 Minerals deposit	Barren
Gray Goo	4	Random Industry technology +1 L-Gate Insight if an L-Gate was discovered	Frozen
Inconsistent Readings	1	+3 Physics deposit	Frozen
Metallic Crystal Formations	2	90-250 Engineering Research 200 Nanites if not Xenophobe 90-250 Society Research if Xenophobe +1 L-Gate Insight if an L-Gate was discovered	Frozen
Alien Activity	3	60-150 Society Research	Gaia	No empire discovered the same anomaly
Movement in the Clouds	2	Lost Amoeba event chain	Gas Giant
Solid Core	3	+2 Exotic Gases deposit and 90-250 Society Research +1 L-Gate Insight if an L-Gate was discovered	Gas Giant
Volcanic Vents	1	+1 Exotic Gases deposit and 60-150 Society Research	Molten
Deep Tunnels	1	Flooded Mounds planetary feature and Watery Grave planet modifier	Ocean
Impenetrable Clouds	1	+3 Minerals deposit	Toxic
Mysterious Construct	5	Special project to gain a unique Admiral leader if AI Policy is not Outlawed	Toxic	No empire discovered the same anomaly
Fleet Signatures	4	+3 Society deposit	Black Hole
Heavy Pulse	2	+4 Physics deposit	Class F Star
Ship Fragments	1	120-350 Society Research	Neutron Star	No empire discovered the same anomaly
Abandoned Settlements	4	Special project to gain the Brain Slug Host trait and 150-500 Society Research if not Machine Intelligence 150-500 Society Research if Machine Intelligence	Any Habitable Planet	No empire discovered the same anomaly
Alien Life	3	Savage Wildlands planetary feature and Hostile Fauna planet modifier	Any Habitable Planet	No empire discovered the same anomaly
Attractive Magnetism	1	Soothing Magnetism planet modifier	Any Habitable Planet	Gestalt Consciousness
Bizarre Blanket	1	90-250 Society Research	Any Habitable Planet
Corrupt Survey Data	4	60-150 Engineering Research and the planet disappears	Any Habitable Planet	No empire discovered the same anomaly
Isolated Ruin	2	Zone A planetary feature	Any Habitable Planet
Megaflora	1	90-250 Society Research	Any Habitable Planet	Machine Intelligence
Resonant Crystals	1	Resonant Crystals planet modifier	Any Habitable Planet	Gestalt Consciousness
Overgrown Ruins	6	120-350 Society Research if not Fanatic Purifiers or Determined Exterminator 90-250 Society Research if Fanatic Purifiers or Determined Exterminator	Any Habitable Planet
Deep Caverns	7	+1 Living Metal deposit and Living Metal technology if not already researched	Any Uninhabitable Planet
Webwork	2	+3 Society deposit	Any Uninhabitable Planet
Silent Behemoth	2	+3 Society deposit and 60-150 Society Research	Any Uninhabitable Moon
Unusual Moon	3	+3 Minerals deposit	Any Uninhabitable Moon	No empire discovered the same anomaly
Encrypted Transmission	2	+1 L-Gate Insight	Any Planet	System has an abandoned L-Gate
Metallic Sands	2	90-250 Engineering Research Nanosands planetary feature if planet is habitable +4 Minerals deposit if planet is uninhabitable +1 L-Gate Insight if an L-Gate was discovered	Any Planet
Supply Ship Wreckage	2	300 minerals or 100 Influence	Any Planet	Genocidal
Interference	1	60-150 Physics Research and 60-150 Society Research	Any Star
Irregular Energy Emissions	4	25 Influence or special project to give a scientist the Meticulous trait	Any Star	Gestalt Consciousness No empire discovered the same anomaly
Mysterious Tanker	5	- Access to the Neural Tissue Engineering technology (for organic empires) - 300—1000 Society research (for Machine Intelligence)	Gaia World	Defeat Corrupted Avatar

Heavy Readings[edit]

If an anomaly is randomly discovered on a star and the system contains a Gateway the anomaly will always be the level 2 anomaly Heavy Readings. Investigating the anomaly will issue a special project on the Gateway. Finishing the special project will grant 90-250 Physics Research and the investigating scientist will gain 2 skill levels and the Paranoid trait.

Repeatable anomalies[edit]

There are two types of repeatable anomalies. The first is the Ancient Signs of Life anomaly, which can only be found on Barren worlds and will add the Terraforming Candidate planet modifier once investigated.

The second are anomalies with the name randomized based on the planet class which will reveal a pre-sapient species on the planet once investigated. Such an anomaly can be triggered once for each planet class, including Gaia and Tomb worlds. Genocidal empires cannot discover these anomalies.

Pioneer 11[edit]

If the Sol system is present in the galaxy a random Asteroid might reveal a level 3 Debris Field Anomaly. Investigating it will discover the Pioneer 11 probe. If the empire is human it will gain 40-100 Influence. If the empire is alien on the other hand it will bring the following options:

Decipher the data disk and gain 120-250 Engineering Research while the science ship leader gains 200 Experience. The location of the Sol system is added to the situation log. Entering the system will grant 80-175 Influence.
Sell the data disk and gain 120-250 Engineering Research.
Use the data disk as furniture and gain 40-100 Influence if Xenophobe or Fanatic Xenophobe.

Media coverage[edit]

A number of anomaly events can be solved in ways that will impact an empire's media views on the empire if not Gestalt Consciousness. Such outcomes bring a Happiness modifier for 10 years.