XCOM2 - PCS Open/Locked

[CaptainPerhaps]

Probably being super dumb but on the Armory screen what does the PCS Open/Locked thing indicate?

[Lionel23]

Personal Combat Stims, they are permenant drug upgrades that raise stats on your soldiers significantly. Highly recommend getting them on soldiers as soon as you can (generally available from Black Market, but also as drops too).

[Raven]

Also, the stims are generally locked, so if you replace one that your soldier is using with a different one, it is lost. There is a bonuses (from NA, I think) that unlocks them, so you can use it on another soldier instead of losing it.

[CaptainPerhaps]

Thanks, how come if I'm in the early game some of my soldiers say Open and some Locked. The ones that are Locked don't seem to have anything in there. Is it just that Rookies can't have them or something?