EMP Grenades/Bombs
So I just learned from Are Gatekeepers vulnerable to EMP Bombs? that Gatekeepers can actually be heavily damaged from EMP grenades/bombs, and can even have a chance to be stunned by them for 2 turns!
I tested and confirmed this myself. In the following screenshot, I used an EMP Bomb on an undamaged Gatekeeper, and it took something like 12 damage, and was also stunned:
Which is weird, because you can't hack a Gatekeeper, so who knew it had robotic components that could be damaged by an EMP?
Flashbangs
I've heard that Flashbangs (or being disoriented) can lower a target's Will stat, which would make it more vulnerable to mind control. I decided to test this out too.
The following is the Will stat of an undamaged Gatekeeper versus a fully upgraded (i.e. has all abilities and fully upgraded Alien Psi Amplifier) Psi Operative using Dominate:
The target's Will is 110%, which reduces my chance to Dominate to 80%. After hitting the Gatekeeper with an EMP Bomb, followed by a Flashbang (so that it's also Disoriented), I checked the chances again, and the Gatekeeper's Will was still 110%.
I've also heard that Flashbangs (and being disoriented) can disable some of the Gatekeeper's abilities, but I haven't tested this out yet, and I'm not sure which abilities exactly would be disabled.
This took a little hunting around to find, but here's a quick breakdown.
Guerrilla Ops, Supply Raids, Landed UFOs, Retaliation Strikes, and Council missions last for a random amount of time, between 18 and 26 hours. This time is determined when the mission is first created and presented to the player. For Guerrilla Ops, where you have 3 missions to choose from, they will all last for the same amount of time.
Other missions, including Alien Facilities and story missions, do not expire.
A "Point of Interest", which is the name for the rewards generated after completing a mission, will last between 9 and 18 days.
Missions will not expire while the Avenger is in the air, but the only effect this has is that you can't expire a mission you're flying to. If you're flying somewhere other than to a mission site, then missions can expire as soon as you land and aren't interacting with some other dialog.
Anyone interested can find the majority of the relevant code in X2StrategyElement_DefaultMissionSources.uc and XComGameState_MissionSite.uc.
Best Answer
Alright, I dug into the code some more and updated my answer.
Here are the number of kills needed for each level, taken from
DefaultGameData_XPData.ini
:However, there's more to it than just straight-up kills.
Every time a unit gets a kill, all the other units on that mission get partial-kills. The game calls these "
KillAssists
", but that's a misleading name because the unit earns aKillAssist
whether or not they did any damage.How much a "
KillAssist
" is worth varies by class(taken from DefaultClassData.ini, variable name
KillAssistsPerKill
)Additionally, Psi Operatives gets a kill bonus called a "
PsiCredit
", worth 1/3rd kill, every time they are hit by Feedback.Finally, if a unit started at any rank above 'Rookie', they'll have additional hidden bonus kills equal to the number necessary for that rank.
Assuming you obtained a unit at 'Rookie', you can see how many kills they have in the armory...
but without a save-file viewer (which doesn't exist AFAIK) you cannot view their
KillAssists
. The best we can do is guesstimate from the number of missions.In my screenshot above, if we assume she's encountered, say, 8 enemies per mission on average, then over 10 missions she's encountered
10*8=80
enemies. That gives her80-29=51
KillAssists, which counts for51/4=12
kills, bringing her approximate kill-total to29+12=41
kills. So she needs around 16 kills or 64 KillAssists to level up to Major.Edit: There is now a mod that shows KillAssists on the soldier info screen: Accurate Soldier XP
Some other interesting things I discovered while code-diving:
KillAssists
andPsiCredits
are not boosted by Wet Works.bUseFullXpSystem=false
). Though, I suppose you could considerKillAssists
andPsiCredits
a form of XP...KillAssists
). There's an option to allow them to level up outside of missions as well.