The Precursors are long dead galactic empires predating even the fallen empires and the curators. Their ruins are scattered across the galaxy for the player to find via anomalies or archaeology sites. Precursor anomalies grant a special project which once investigated grants a small amount of Engineering, Physics or Society research as well as a precursor artifact. 6 artifacts are required to reveal the location of a precursor's home system.
If every precursor anomaly has been investigated but no empire managed to collect 6 artifacts a random event can trigger every 20 years and add another precursor anomaly on one of the previously investigated planets. The time is lowered to 13.3 years for Gestalt Consciousness empires.
AI empires can also sell a discovered artifact to Player empires for 1000 Energy. If the Player empire has the Warrior Culture civic it can threaten the AI empire to surrender it for free, the success rate depending entirely on both empires' Relative Power. Empires that hold a Protective, Friendly or Loyal attitude will offer the artifact for free instead of asking for payment. Each AI Empire will only offer an artifact once.
|Available only with the Ancient Relics DLC enabled.|
Once a Precursor homeworld has been discovered the empire will gain an artifact action to spend 50 Minor Artifacts to start a special project to delve into the secrets of one of the Precursor civilization. Finishing the special project will grant a permanent empire benefit. If the DLC is installed precursor anomalies will also grant 1-5 Minor Artifacts.
Archaeological Sites are areas where remains of ancient civilizations have been preserved relatively intact. They can be discovered while surveying, generated at game start or uncovered a few years after a planet is colonized. Each time a planet is surveyed there is a 1.25% chance of an archaeology site being discovered.
A site can have 1-6 Chapters in addition to an introduction Chapter. Each Chapter has its own narrative and rewards and has to be unlocked before it becomes visible. Chapters are unlocked via Excavation. As long as an Archaeological Site is within an empire's borders that empire can task a Science Ship to excavate the site. The duration of an Excavation is determined by the Archaeological Site's Difficulty rating and can be reduced by -25% if the Scientist on the Science Ship has the Archaeologist trait. As the Scientist goes through excavations, it will generate a random number from 1 to 10 and add modifiers to the result, with the following formula: Result = dice roll + archaeology skill + clues − difficulty. Additional events can also trigger at the end of each excavation.
From Gateway Sent
|Rewards||1-5 Minor Artifacts||1-5 Minor Artifacts|| 1-5 Minor Artifacts
90-250 Physics Research
| 1-5 Minor Artifacts|
120-350 Engineering Research
On the Shoulders of Giants sites
|Available only with the Federations DLC enabled.|
The On the Shoulders of Giants Origin adds a lengthy Archaeological Site chain in the empire home system. The narration of the last two chapters of the final site are random but the rewards are always the same.
Ancient Relics sites
|Available only with the Ancient Relics DLC enabled.|
All other Archaeological Sites in the game require the Ancient Relics DLC to be found.
|Site||Chapter 1 rewards||Chapter 2 rewards||Chapter 3 rewards||Chapter 4 rewards||Chapter 5 rewards||Chapter 6 rewards||Requirements|
|Ancient Battle Site||None||Uninhabitable planet|
|Moon Bump||1-5 Minor artifacts||3 Outcomes and if already researched:
|Trench World||1-5 Minor artifacts||3 Outcomes and if already researched:||Barren|
|Beautiful Bubble||1-5 Minor artifacts||1-5 Minor artifacts||150-500 Society research||Uninhabitable planet|
|Beneath the Waves||1-5 Minor artifacts||1-5 Minor artifacts||Ocean|
|Get to the Bottom||1-5 Minor artifacts||1-5 Minor artifacts||Ocean|
|City of Bones||5 Minor artifacts||5 Minor artifacts||Dry|
|Déjà Vu Dig||1-5 Minor artifacts||1-5 Minor artifacts||3 Outcomes and if already researched:||Uninhabitable planet|
|Hole in the Ground||1-5 Minor artifacts||1-5 Minor artifacts||Random Technology||Uninhabitable planet|
|Strange Flows||1-5 Minor artifacts||1-5 Minor artifacts||Random Technology||Molten|
|Too Angled||1-5 Minor artifacts||1-5 Minor artifacts||Random Technology||Uninhabitable planet|
|Dotted Archipelago||1-5 Minor artifacts||1-5 Minor artifacts||Random Society Technology||Ocean|
|Get Inside||1-5 Minor artifacts||1-5 Minor artifacts||Random Society Technology||Uninhabitable planet|
|Frozen Complex||1-5 Minor artifacts||1-5 Minor artifacts||Frozen|
|Subterranean Hollows||1-5 Minor artifacts||1-5 Minor artifacts||Habitable planet|
|Mutant Fossils||5 Minor artifacts||5 Minor artifacts||Mutation Vats Planetary Feature||Tomb world|
|Robot Debris||1-5 Minor artifacts||1-5 Minor artifacts||Asteroid|
|Target from Orbit||1-5 Minor artifacts||1-5 Minor artifacts||3 Outcomes and if already researched:||Uninhabitable planet|
|Shot into the Ground||1-5 Minor artifacts||1-5 Minor artifacts||3 Outcomes and if already researched:||Uninhabitable planet|
|Cut to Fit||1-5 Minor artifacts||1-5 Minor artifacts||3 Outcomes 10% / 45% / 45%:||Uninhabitable planet|
|Sky Glow Hymn||1-5 Minor artifacts||1-5 Minor artifacts||3 Outcomes, 2 Rewards 66% / 33%:
|Warmer Climates||1-5 Minor artifacts||1-5 Minor artifacts||3 Outcomes and if already researched:||Uninhabitable planet|
|The Hive Coral||1-5 Minor artifacts||1-5 Minor artifacts||3 Outcomes, 2 Rewards 66% / 33%::||Ocean|
|Any Other Rock||1-5 Minor artifacts||1-5 Minor artifacts||1-5 Minor artifacts||Permanent +5% Unity Empire modifier||Molten|
|Anyone Home?||1-5 Minor artifacts||1-5 Minor artifacts||1-5 Minor artifacts||Random Society Technology||Uninhabitable planet|
|Asteroid Blast Door||1-5 Minor artifacts||1-5 Minor artifacts||1-5 Minor artifacts||50-100 Minor artifacts||Asteroid|
|Gas Giant Structure||1-5 Minor artifacts||1-5 Minor artifacts||1-5 Minor artifacts||Gas Giant|
|Relic Rails||1-5 Minor artifacts||1-5 Minor artifacts||1-5 Minor artifacts||Housing building|
|The Echoes Inside||1-5 Minor artifacts||1-5 Minor artifacts||1-5 Minor artifacts||1000-10000 Society research||Barren|
|The Endless Expanse||1-5 Minor artifacts||1-5 Minor artifacts||1-5 Minor artifacts||10-30 Minor artifacts||Frozen|
|Ebb & Flow||1-5 Minor artifacts||1-5 Minor artifacts||1-5 Minor artifacts||3 Outcomes, 2 Rewards 66% / 33%:
|The Phoenix Collective||1-5 Minor artifacts||1-5 Minor artifacts||1-5 Minor artifacts||3 Outcomes and if already researched:||Uninhabitable planet|
|Fossilized Remains||1-5 Minor artifacts||1-5 Minor artifacts||1-5 Minor artifacts||1-5 Minor artifacts||Colony|
|Kleptomaniac Rats||6-10 Minor artifacts||6-10 Minor artifacts||6-10 Minor artifacts||6-10 Minor artifacts||Relic world|
|Message in the Dust||1-5 Minor artifacts||1-5 Minor artifacts||1-5 Minor artifacts||1-5 Minor artifacts||Habitable planet|
|Whispers in the Stone||1-5 Minor artifacts||1-5 Minor artifacts||1-5 Minor artifacts||1-5 Minor artifacts||Mining District|
|Ancient Tomb||1-5 Minor artifacts||1-5 Minor artifacts||1-5 Minor artifacts||1-5 Minor artifacts||1-5 Minor artifacts||
|Crashed Starship||1-5 Minor artifacts||1-5 Minor artifacts||1-5 Minor artifacts||1-5 Minor artifacts||1-5 Minor artifacts||10-30 Minor artifacts||Uninhabitable planet|
|The Grand Herald||1-5 Minor artifacts||1-5 Minor artifacts||1-5 Minor artifacts||1-5 Minor artifacts||1-5 Minor artifacts||Dry|
Precursor Archaeology Sites are visible only to the empire that starts the event chain and are used to advance the Baol and Zroni event chains. When a Zroni Archaeology Site is discovered the planet will gain a deposit of 2-4 Zro.
The Sentinels is an Archaeology Site with slightly different mechanics. It can be discovered after a planet is colonized and unlike all others it brings a choice when completely excavated. When discovered it adds an Archaeological Site blocker to the colony.
|Chapter 1||Chapter 2||Chapter 3|
|Rewards||1-5 Minor Artifacts||1-5 Minor Artifacts|| 1-5 Minor Artifacts|
Archaeological Site blocker removed
When the site is completely excavated the empire will get the following choices:
- If not Xenophobe or Fanatic Xenophobe gain an Unity from Jobs planet modifier and a permanent blocker.
- If not Xenophobe or Fanatic Xenophobe issue a special project to open the Sentinels. When the special project is complete the empire will have the option the hear the Sentinels or attack. Attacking will have the Sentinels invade the colony with 9 armies. Hearing them out will bring the option to either gain a permanent blocker and 9 defense armies or be hostile and have the Sentinels invade the colony with 9 armies. The invasion has an Army Strength of roughly 2400.
- Issue a special project to destroy the Sentinels. When the special project is complete the will be invaded by 9 armies. If the armies are defeated the colony will gain the Sentinels planetary feature and empire will be offered to either gain 150 Influence or issue a special project to see what the Sentinels were guarding. Finishing the special project will bring the following options:
- Gain 300 Influence and the Cheap Thrills planet modifier that gives -10% Pop Consumer Goods Upkeep and a +5% Happiness.
- Gain the The Evermore planet modifier that gives +10% Research.
- Gain access to the Replicate the Evermore special project.
- If Militarist or Xenophobe gain 300 Influence and access to Cheap Thrills planet modifier that gives +10% Militarist Ethics Attraction, +10% Xenophobe Ethics Attraction, -10% Consumer Goods Upkeep and +5% Happiness.
If at the end of an Excavation phase the result is not high enough to grant a Clue or finish the Chapter then one of the following events may happen:
- Science Ship Scientist dies, -2 Clues
- Archaeology team members die, -1 Clues
- A dangerous situation is avoided, +3 Clues
- Choice to pay 100 Energy to get +3 Clues or do nothing and get -2 Clues
- Science Ship Scientist gains the Maimed trait
Assuming you never get any of the aforementioned events, the average number of rolls required to complete the chapter can be read from this table. "S + C - D" is the scientist's archeology skill, plus clues, minus difficulty. A level 3 scientist with Curator Archaeology Lab tech researched and 2 clues, excavating a level 4 chapter, would have an S + C - D of 5 + 2 - 4 = 3, and will need slightly under four and a half more rolls, on average, to complete the chapter.
|S + C - D||Expected Rolls|