XCOM: Enemy Unknown

You have to wait until you kill or capture a sectoid commander and research it. You'll then be able to build a Psilab building in your base. You can only test 3 people at a time, and it takes 10 days for the testing. Easiest thing to do is save before the testing, then just go down the list of soldiers 3 at a time and fast forward time in mission control. Just skip any ufo detection or abductions. If after 10 days all 3 soldiers came up as duds, just reload your game and test the next 3 soldiers in the list.

the solution of Lewd Llama 69 is correct, this is only an additional tipp.

i just wanted to add that there is a way to get the psi ability for EVERY soldier in your barracks. and you also can get the gift for ALL 3 tested soldiers at once. though this takes a little time to do, it can be really helpfull on the higher difficulties to have a team full of psi soldiers.. and it's just neat anyway..

before doing it i recommend to have 2 or even 3 copies of your actual save (just save 3 times in a row) to make sure you don't overwrite an important savegame by accident..

1.) to start, simply put the soldier(s) you want to have psi ability on into the psilab
2.) save the game
3.) fast forward time in mission control, skip every event till the psi testing result comes up

4.)1. if the soldier(s) DO NOT HAVE psi ability continue with step 5.
4.)2. if some of the soldier(s) DO HAVE psi ability skip steps 5. to 7. and continue with step 8.

5.) reload the original savegame you started with before starting with step 1.
6.) simply go to the situation room, open up the black market and sell something (i usually sell 1 alien alloy because there are always enough of them around) or alternately you can also go to the engineering and buy something, or start a new foundry project. all of this will somehow reset the calculation for the next psi test. (if it doesn't work after a few attempts try change to sell 2 alien alloys or 1 elerium instead, sometime that helps changing the result)
7.) now put the same soldier(s) that failed in the last test run into the psi test again and repeat steps 1. to 4. until you have at least one soldier with psi ability (it can happen that you have to try more than one time to get it, specially if you want the gift on only one specific soldier)

8.) now that you know which soldier(s) will have the psi, reload the game you saved after putting the soldier(s) into the test chamber (step 2.)
9.) remove all soldier(s) from the test that will NOT have the psi.
10. save the game again

now you have your original savegame with at least one soldier already in the test that will get psi in 10 days guaranteed. to get all 3 slots full with psi capable soldiers start again from step 1. and just fill up the other free slots until you have all 3 full with future psi soldiers (you can also use those that you just removed but first use step 6. to reset their chance on psi..)


i hope this was understandable and somehow helpful. if you going to leave negative feedback please tell why in the comments or in a pm, thanks.