TL;DR is at the bolded "
HOWEVER" below.
Each artifact has a "preferred" reward. The following lists mean this:
Category Name of the listed rewards
- Reward 1 name: Artifact 1 name, Artifact 2 name
- Reward 2 name: Artifact 6 name
This list means that Artifact 1 and Artifact 2 both "prefer" to give Reward 1; and Artifact 6 "prefers" to give Reward 2.
Old Earth category rewards (unlocks buildings):
- Warp Spire (domestic trade routes +50% yield): Suspended animation chamber, Near lightspeed accelerator, Polypeptor organic antifreeze, High mass friction welder
- Drone Command (work 2 more tiles than a city has citizens): Senor caffeine, Drone hive mind, Clean air generator, Butuiller family drone
- Old Voice Archives (+10% yields when at war): Personal meditaion helmet, Toymark media cube, Messiah stradivarius, Isotopic decay three
- Pan Spectral Observatory (orbital units +100 production, orbital strike range +2): Volumetric component printer, Plasma turbine engine, Silver pont navigation gyroscope, Impossible drive
- Frontier Stadium (city defense +10, military units start with 1 free promotion): Hull repair suit, Jowler ball field set, Lineage two interactive family tree, Thoughtful chess set
- Xenomass Bath House (culture +2, units in city heal 100% after 1 turn): Collapsing family library, Speech compression computer, Population estimation computer, Telemed remote operating theatre
All these listed artifacts themselves belong to the Old Earth category.
Alien World category rewards:
- Zygotic Engineering (outpost growth speed +100%): Ross weed, Noose vertebrae, Giant pheromone sack
- Sky Chitin (air units +50% strength and +3 range): Lattus ore, Cloud coral, Macroelectrons, Breeze weed, Carbon hail
- Counter Battery Fire (siege units ability unlock: lower enemy unit's defense by 20% for the rest of your turn): Seismic sounding fork, Zero point soil, Pressured magma sample, Mobius horn
- Vapor Shield (all units +100% defense when embarked): Jelly stalk ring, Soap seed, Acidic crystals, Flexible keratin tusk
- Projected Chasis Construction (worker movement +2): Cocoon flies, Crystal shrimp pupa, Floating canopy worms, Electric brain moss
- Tidal Navigation (naval units defense against ranged attacks +100%): Crystal shrimp adult, Carnivorous hive heels, Heterophobic solution, Tungsten bubbles
All these listed artifacts themselves belong to the Alien World category.
Progenitor category rewards:
- Tesselation Foundry (military units cost 30% less production): Geon spores, Single pass geometry, Tesselation vault, Atomic tesselator
- Dimension Folding Complex (city population unhealth -50%): Jelly space, Planes of dimensional influence, Dimension oven, The folder
- Machine Assisted Free Will (tech costs 30% less): Void spectre, M theory capsule, Sporadic listener, Unknown progenitor
- Temporal Calculus (all units visibility +2): Auratic magnet, Models of entropy, Casual looking glass, Deviation fork
- Quantum Politics (virtue acquisition speed +100%): Superposition containment device, Superposition, Decoherence chamber, Fundamental object
- Relativistic Data Bank (all cities -1 intrigue per turn): Temporal injector, String weaver, Fixed position locator, Bright matter
All these listed artifacts themselves belong to the Progenitor category.
Hybrid category rewards:
- Tesseract Targeting: cities can bombard through terrain obstacles
- Soul Discerner Training: covert operations speed +25%
- Xenoanthopology: discover artifacts 20% more often
- Slumber Slaughter Extract: worker build speed +50%
- Ground Penetraing Lidar: expedition speed +100%
- Statecraft: +2 diplomatic capital from agreements
Note that these rewards are not "preferred" by any artifact.
How the code works:
EIL5 (Explain Like I'm 5) version:
- Each artifact belongs to a "category" (i.e. Old Earth=OE, Alien World=AW, or Progenitor=Pr), and each artifact has a "preferred reward".
- A special "Hybrid" category has no artifacts, only rewards.
- What you get after combining 3 artifacts depends on the preferred rewards of those 3 artifacts.
- If all 3 preferred rewards are the same, you get that reward 100%. Else it's equal chance among the possible rewards.
- When all the preferred rewards are rewards you've already got, then you have equal chance to get any one of the remaining rewards in the categories to which the 3 artifacts belong.
- When any of the 3 artifacts you combine belong to a different "category", or if you have exhausted all other rewards, then all the Hybrid rewards are thrown in as candidates.
So basically if you're aiming for OE/AW/Pr rewards, you can aim for 100% if you have 3 artifacts listed under your target reward. Failing 100%, you should aim to have at least 2 artifacts that prefer your target ward, then add in a 3rd artifact from the same category. This gives you a 66% chance. Failing that you can combine artifacts from the same category but all preferring different rewards, giving you a 33% chance.
If you throw in even 1 artifact from a different category, you pollute your draw with everything in the Hybrid category.
Note that there's an interesting little trick. Any artifact that prefers a reward you have already received can be used as filler for other rewards from that same category without lowering the probability.
For example, let's look at only the Drone Command and the Old Voice Archive. Say you used Senor Caffeine, Drone Hive Mind, and Clean Air Generator to 100% get Drone Command, and you still have the Butuiller Family Drone artifact. Then you could combine Personal Meditaion Helmet and Toymark Media Cube with the Butuiller for 100% chance to get the Old Voice Archive, because you can't receive the Drone Command reward again. (
Note that this only works with all artifacts in the same category.)
Another twist is that if you use 3 artifacts from the same category, yet you have received the preferred reward of all 3 artifacts, then you have an equal chance to get one of the remaining rewards from that category.
For example you have received War Spire, Drone Command, and Old Voice Archives. Then you combine Suspended Animation Chamber + Senor Caffeine + Personal Meditation Helmet, then you will receive one of the remaining 3 rewards in the Old Earth category with each reward having equal chance.
HOWEVER, in practice, because you can see the result of the combine and are able to cancel it if you don't like it, the optimal way to game the system is to try out all the different combinations as long as you have at least 1 artifact that prefers to give the reward you want. For example, Machine Assisted Free Will (tech costs 30% less) is preferred by Void spectre, M theory capsule, Sporadic listener, and Unknown progenitor. The moment you get one of these 4 artifacts, you should try to combine it with all your other artifacts (regardless of their category and preferred reward) and you might just get lucky and end up with Machine Assisted Free Will.
Order of the combine doesn't matter because the possible reward "List" is sorted each time before taking the random number. Don't bother closing the window or clearing the slots and putting the same things back on because results won't change within the same generated game world. Results may change after save/load if you enabled the advanced setup option to get a new random seed each time. Also, results
may change after each combine because the pool of possible rewards are reduced after each combine.
So the simplest rules are:
- If you want OE/AW/Pr rewards, try all the combinations of artifacts within the same category as the reward you want.
- If you want Hybrid rewards, try all the combination that uses artifacts from at least 2 different categories.
- After you have tried all combinations and the reward you want didn't show, bad luck, try again once you get another artifact that you can use in the two rules above.
Lastly, please remember that I do not guarantee this is correct. It's what I gathered from skimming through the code. I may very well be wrong.
