OpenXcom Forum

OpenXcom => Open Feedback => Topic started by: alienjon on November 20, 2019, 06:03:05 am

Title: Mind Control and LoS
Post by: alienjon on November 20, 2019, 06:03:05 am
Coming back for a campaign (first time in a few years) and progressed to the point of higher-level sectoids with mind control abilities.  I recall from the past (or at least thought) that psionics could only occur if an enemy has line of sight (not necessarily the alien with the mind control capabilities, but any enemy in line of sight of any friendly would allow a psi-capable alien to take advantage of).  I'm finding that this doesn't seem to be the case as I've been regularly on the receiving end of psionic attacks without any apparent enemy nearby.  As an example, I'm currently in a landed very large UFO mission and after only a few turns it seems that I'm constantly being barraged by psi attacks, even though the entire outside of the UFO has been cleared (I'm progressing inward, at this point, but haven't actually entered the UFO yet).

I looked online and the only info I can find is from the wiki (https://www.ufopaedia.org/index.php/Psionics), which states:
Quote
Alien Psionics Targeting

If any of your squad members, even a HWP, is visible to any alien during the Alien Turn, every member of your squad is at risk of attack from any psionic aliens, regardless of whether the spotter is psionic.

It should be noted that once you pass Turn 20, or if there are only 1 or 2 aliens left on the map, all of your squad members and their locations are revealed to the AI. This means you can expect a steady stream of psionic attacks after that turn if there any of the remaining aliens are capable of Psionic attack.

I may be about turn 20 now, but this has been going on for turns well before turn 20.  Did OpenXcom change the rules on this, or am I missing something obvious?
Title: Re: Mind Control and LoS
Post by: 7Saturn on November 20, 2019, 12:26:03 pm
As far as I know, it is also sufficient to be »remembered«. On alien has seen someone of your team, and remembers that one for two turns or so. Maybe in combination, that leaves you at the disadvantage all the time. But I do remember that behavior from original X-COM as well (which is the one thing, that makes psi really unfair in the beginning, especially on the first terror mission, if it is with Sectiods: you are constantly screwed with no means of retaliation at all).
Title: Re: Mind Control and LoS
Post by: Empiro on December 13, 2019, 03:57:38 am
Yeah, that's always been a huge problem when they start panicking your guys in the back of the Skyranger. There's no way they could have seen those folks at all.

I don't know if it's possible to make these two mods:

I think having both would go a long way to make Psi/MC more balanced for players and less cheaty for aliens.
Title: Re: Mind Control and LoS
Post by: cptelerium on December 27, 2019, 02:59:30 am
which is the one thing, that makes psi really unfair in the beginning, especially on the first terror mission, if it is with Sectiods: you are constantly screwed with no means of retaliation at all).

My top list of things that scare me as overpowered and "unfair"  (but war is never fair...) in Xcom:

1. this (MC by invisible enemies)

2. blaster bombs, suicidal style

3. 1-shot plasma kill of best solider even though he had flying armour and full HP

For 1 I guess just ruuushing it works (and heavy smoke around everyone for first 3-6 rounds + scouting ahead with tank), and too weak guys eventually die leaving more resistant as natural selection (still it's a R.I.P with big ufo sectoids and most ethereals)

For 2 also rushing especially if you get to leader/commander of who ever has B.L. in big UFOs, if he is close he usually doesn't fire (no suicide)

For 3, well that's life.


Title: Re: Mind Control and LoS
Post by: Countdown on January 09, 2020, 01:45:18 am
Hi alienjon, I'm actually returning to the game after a couple years away as well. MC and LOS is something I've tested quite a bit and started a thread (https://openxcom.org/forum/index.php/topic,4664.msg66482.html) on back in 2016.

What I found was that aliens can attack any soldiers that have been spotted and are "remembered" as 7Saturn said. But they do have to have spotted them at some point. If they have been in the back of the skyranger and never seen by an alien or one of your mind controlled soldiers, then they can't be the target of psi attacks (until the turn 20 rule comes into effect of course).

Yeah, that's always been a huge problem when they start panicking your guys in the back of the Skyranger. There's no way they could have seen those folks at all.
That isn't actually the case. They have to have seen them at some point. Maybe they were spotted by one of your soldiers when they were mind controlled, or an alien was near enough the open door of the skyranger. But aliens can't launch psi attacks if they've never spotted the soldier.

  • Make it so that you can only target entities your own (permanent) soldiers see. i.e. get rid of chain controlling, where you control one alien to scout and reveal more, and then control them, and so on.
I like this idea though since infinitely chaining psi attacks from alien to alien is so cheesy. Alternatively, you can just change the ruleset to make psi amps require line of sight.
Title: Re: Mind Control and LoS
Post by: The Reaver of Darkness on January 09, 2020, 02:04:09 pm
Mind control was never limited by line of sight in the original game, but openxcom offers that as an option. Just turn on the UFO Extender mod for Psionic LOS.
Title: Re: Mind Control and LoS
Post by: Empiro on September 28, 2023, 11:35:04 pm
Reviving this a bit, but could there be an intermediate setting for this: aliens can use PSI attacks without direct line-of-sight from the caster to the target. However, it can only done on targets that aliens actually spotted this turn, and not any of the "if one soldier is seen then all are targets" or "aliens automatically see everyone after turn 20" BS. Aliens move around randomly enough that I don't expect the PSI user to actually see their target, but targeting guys in the middle of your craft is just some next level crap.

I think the most balanced approach would be to require direct Line-of-Sight for player users to the target, and allow aliens to use PSI if any of their units directly and actively see the target.
Title: Re: Mind Control and LoS
Post by: Meridian on September 29, 2023, 01:01:22 am
Yes, everything can be done. Someone just has to do it :)

To be more helpful, one would have to give/mod minimum intelligence value to all aliens.

and not any of the "if one soldier is seen then all are targets"

Anyway, I am replying mainly because of the myth above.
This was not true in the original and is also not true in openxcom.

Aliens have to "know about you" to use psi, which can happen only by actually seeing you (same turn or earlier, depending on intelligence), or by "knowing about (not seeing) everyone at turn 20, sometimes at turn 10".
Title: Re: Mind Control and LoS
Post by: AlesiSanchez on January 02, 2024, 10:16:20 am
I am confused by this mechanic, I have just started a terror mission, spotted two aliens, but I'm 99% certain they did not see the guy they subsequently sent beserk because he was within the middle of a smoke cloud, was not spotted and was hit at the end of the 2nd turn (after he first exited skyranger into smoke and shot at an alien someone else spotted - he never left what I'm 99% sure was invisible area of the smoke). So I have no idea how they "knew about" him. I think he did fire at and hit one of the aliens (from inside smoke).

Title: Re: Mind Control and LoS
Post by: Meridian on January 02, 2024, 10:26:55 am
Hitting an alien also makes you spotted.

https://github.com/OpenXcom/OpenXcom/blob/master/src/Battlescape/ProjectileFlyBState.cpp#L794
Title: Re: Mind Control and LoS
Post by: AlesiSanchez on January 02, 2024, 10:46:36 am
Thank you so much. I see your comments everywhere helping out (obviously in addition to your mods!). Thank you sir.

Do rockets and grenades count as 'hitting' or does 'indirect' fire keep you hidden? 

Title: Re: Mind Control and LoS
Post by: psavola on January 02, 2024, 11:02:40 am
As I read the code with my limited understanding, indirect fire (grenades, splash damage from rockets, blasters, etc.) should not trigger this. However, if you fire a rocket and it hits the target directly, at least then it get triggered. This is why in some cases (and with some specific sniper/spotter mods), you may want to target a ground square rather than enemy unit with your indirect fire.

I suppose apparently also a melee attack doesn't trigger this (if the unit was facing another way and didn't react and notice you visually). This was a somewhat surprising find for me.
Title: Re: Mind Control and LoS
Post by: AlesiSanchez on January 02, 2024, 11:44:34 am
I bow in appreciation gents.  8)
Title: Re: Mind Control and LoS
Post by: Meridian on January 02, 2024, 01:49:57 pm
As I read the code with my limited understanding, indirect fire (grenades, splash damage from rockets, blasters, etc.) should not trigger this.

Nope.
Grenades, splash from rockets, etc. trigger it too.

https://github.com/OpenXcom/OpenXcom/blob/master/src/Battlescape/BattlescapeGame.cpp#L719
Title: Re: Mind Control and LoS
Post by: psavola on January 02, 2024, 02:45:05 pm
Nope.
Grenades, splash from rockets, etc. trigger it too.

https://github.com/OpenXcom/OpenXcom/blob/master/src/Battlescape/BattlescapeGame.cpp#L719

I stand corrected. It seems that I was correct on the part that stunning enemies don't get you spotted, though, so at least an indirect hit (that doesn't kill the enemy) doesn't count.
Title: Re: Mind Control and LoS
Post by: Juku121 on January 02, 2024, 05:35:01 pm
It seems that I was correct on the part that stunning enemies don't get you spotted, though, so at least an indirect hit (that doesn't kill the enemy) doesn't count.
Meridian's reference means you get 'blamed' for the kill, not the hit. Stun is separate from that, you can 'stun-kill' someone and it doesn't trigger the omniscience. Conversely, you can make an enemy burn or bleed and be 'seen' three turns later when the enemy succumbs to these injuries.

All in all, it's a moderately confusing mechanic. Especially in conjuction with 'spottedForSnipers'.
Title: Re: Mind Control and LoS
Post by: iodsnips on January 02, 2024, 10:34:09 pm
The intelligence statistic is 0 for all humans, aww!  For aliens it ranges from 2 to 8 and is unaffected by difficulty settings.  Intelligence is a number that correponds to the number of turns the alien will remember the location of your troops.  Like it's been mentioned, aliens can be affected by something after several turns thus extending how long they remember the location of your troops from how long you might expect.  Alien ranks plays a big role in-between the different species for their intellect.

The only alien combos that have the minimum 2 intellect:
Snakeman Soldier
Muton Soldier
Reaper

The only aliens that have the maximum 8 intellect:
(3 of 4 below are the only aliens to have 0 aggression too!)
Floater Leader
Floater Commander
Sectoid Commander
Ethereal Commander (has aggression of 1)

Special mention for only the terror aliens along with their intellect:
Reaper 2
Silacoid 3
Zombie 3
Chryssalid 4
Celatid 4
Sectopod 4
Cyberdisc 5

Some unique alien statistics that they get:

"Intelligence of the alien ranked from 2-8. This number correponds to the number of turns the alien will remember the location of your troops."

"Energy Recharge. This number represents how fast a unit will recover Energy lost due to movement."
  The human mechanic to this a soldiers starting TUs to determine Energy Recovery & can never change for that soldier. 50TU=16, 51-53=17, 54-56=18, 57-59=19, 60=20

"VPS, The number of Victory Points X-COM will get for killing that alien."

"Aggression is a number between 0 and 2. The larger the value, the more aggressive the alien will be. High ranking aliens usually prefer to stay concealed, rather than get involved in a raging fire-fight."
Title: Re: Mind Control and LoS
Post by: AlesiSanchez on January 03, 2024, 01:58:32 am
Many thanks again good Sirs. 
Title: Re: Mind Control and LoS
Post by: AlesiSanchez on January 08, 2024, 08:50:51 am
Just a thought... I presume that proximity mines do not reveal the soldiers like other grenades, rockets, explosives etc?

I thought this might be the case because prox mines (iirc) do not give XP etc to person throwing so I thought perhaps they similarly do not reveal person throwing?

Nope.
Grenades, splash from rockets, etc. trigger it too.

https://github.com/OpenXcom/OpenXcom/blob/master/src/Battlescape/BattlescapeGame.cpp#L719
Title: Re: Mind Control and LoS
Post by: Meridian on January 08, 2024, 09:09:41 am
Just a thought... I presume that proximity mines do not reveal the soldiers like other grenades, rockets, explosives etc?

I thought this might be the case because prox mines (iirc) do not give XP etc to person throwing so I thought perhaps they similarly do not reveal person throwing?

It applies to proxies too.

And they give (firing) XP too to the throwing person.
Title: Re: Mind Control and LoS
Post by: AlesiSanchez on January 08, 2024, 12:22:19 pm
Thank you again good sir.