|“||This facility will allow us to discover and develop the latent psionic abilities of our soldiers. If they have any such capabilities, using them in the field will increase their strength.||”|
– Engineering description, XCOM: Enemy Unknown
Facility Maintenance: §30 per month
Once this facility is complete, you may test your soldiers for Psi-Abilities. All testing is done by selecting "Visit The Psi Labs" from the Barracks menu. Up to three soldiers can be tested at the same time. Psionic testing will take 10 days to complete; whether or not a soldier is psionically "Gifted" is revealed at the end of this period. Soldiers that are undergoing testing cannot be sent on missions unless removed from testing early; however, doing so means that retesting will require completion of a new 10-day testing period.
- The Psionic Labs room itself does not seem to have any adjacency benefits or bonuses.
- This lab can be used to "select" soldiers for the Base Defense Mission. Although you can't actually select a squad for this mission, you can still place which soldiers you feel aren't suited for the Base Defense into the psi-labs and re-arrange your soldier list as to who will be starting, then you can remove them when you finish the mission.
- Having a soldier with Psi-Abilities is essential to completing the game.
- The coding for an individual soldier's chance of having the Gift can be seen here.
- The basic formula gives a soldier's chance of becoming Gifted as their Will stat divided by 4 (the default PSI_GIFT_CHANCE value); so a Colonel with 108 Will would have a 27% chance.
- If either 0 or 1 currently gifted soldiers are found, a soldier will receive a bonus to their chance which increases at lower levels.
- If there are zero current psionic soldiers, the bonus is 75 (rookie), 55 (squaddie), 35 (sergeant), and 15 (lieutenant).
- If there is one current psionic soldier, the bonus is 35 (rookie) and 15 (squaddie).
- It is unknown whether psionic soldiers created in the top two slots of a test pool of three count against this limit.
- Thus, it may be ideal to only test squaddies until you have two psionically gifted soldiers. This ensures knowledge of what class will receive the gift, and that the soldier in question has a reasonable initial will jump (50-52 as a squaddie with iron will upgrade), while still receiving a large bonus to gifted chance (55% for the first soldier and 15% for the second). After this point, it is preferable to level up soldiers all the way to Colonel before testing - but their odds of being gifted will still be fairly small (25% for a Colonel with 100 will).
- The values for which an individual soldier's Gifted status is determined appear to be influenced by who else is tested at the same time as well as what slot order they are placed in (See Random vs Seed Guide for more information):
- So if you have a set of three soldiers that really need Psi-Abilities, you should save first when placing them in the Psionic Lab. Test if any of them are Gifted, and, if at least one of them is, reload, "cancel" the others, then put them back into the testing list (without removing the Gifted one), and then repeat until you have them all Gifted (the "Gift" resets when you remove someone and then add them again).
- In turn if you really want a single soldier to acquire Psi-Abilities, you can save before testing him and reload, if he is not Gifted.
- Note neither of these are possible to perform if you are playing in Ironman mode.