AI Bugs, Improvements & Suggestions

[Gijs-Jan]

Tech. Info

v21 Experimental Build 4, balance update

Observed Behavior

Light drones are too passive, they don't fire unless right next to a target.

Desired Behavior

In line with their role as a supportive suppresion unit, they should always fire whenever possible, regardless of hit chance, and try to stay at long range

This should be fixed now.

[Ol' Stinky]

In the UFOcontents folder, the .xmls that determine the aliens around for each type of mission are given various scripts. Aggressive, passive, defensive, command. I'm guessing they control stuff like spawn location and what the goal variable from aiprops.xml does. What's the purpose of the passive script, and how does it differ from aggressive in practice? Can we mod these scripts, and if not, are we ever going to be able to?

[Chris]

Yes, you can mod them. On crash site missions, Passive are aliens that stay in one spot and reaction fire at units that come close (i.e. snipers). Defensive aliens will try to defend the UFO, but are a bit more aggressive than Passive aliens. Aggressive aliens will actively search for Xenonauts to attack.

[Ol' Stinky]

Thanks for clearing that up.

Can suppression and stun damage be factored into the decision making process or is it too late for that? Like 2 stun damage being worth 1 real damage, and 5 suppression being worth 1 damage. Aliens only have damaging grenades at the moment; if someone were to mod in a stun grenade for lower alien ranks, is there a way to get aliens to throw those grenades? Right now it seems that only pure damage is considered.

[Gijs-Jan]

I'll take a look at this. I'll expose the weights through the aiconfig.xml file.

[Ol' Stinky]

You're too kind. Ta.

[Caaygun]

Yes, you can mod them. On crash site missions, Passive are aliens that stay in one spot and reaction fire at units that come close (i.e. snipers). Defensive aliens will try to defend the UFO, but are a bit more aggressive than Passive aliens. Aggressive aliens will actively search for Xenonauts to attack.

Hmm. I was suspecting this was the case. So my strategy of staying near the dropship for a few turns to wait for aliens to come to me before moving out was indeed a good choice. Is this intended player behaviour?

[Chris]

Hmm. I was suspecting this was the case. So my strategy of staying near the dropship for a few turns to wait for aliens to come to me before moving out was indeed a good choice. Is this intended player behaviour?

No, but it's a valid tactic imo. It's certainly not worth removing the aggressive aliens in order to "fix" it.

[Ol' Stinky]

They don't roam that aggressively. Depending on how much they value allied influence, you're also giving them time to group up if they're scattered, too: life's easier if you can pick them off while they're too far away to support each other.

[Caaygun]

They don't roam that aggressively. Depending on how much they value allied influence' date=' you're also giving them time to group up if they're scattered, too: life's easier if you can pick them off while they're too far away to support each other.[/quote']

Thankfully () they lack the team AI to strategically group themselves. They also apparently don't prioritize xenonauts over civilians, the income penalty of whose death is less punishing than losing soldiers by being too agressive to save civilians or hunt aliens. Though I have noticed that they use team sight effectively to scout and attack my soldiers, but not team movement.

[Belmakor]

Observed:

Aliens can't open doors in ufos or bases when there are xenonauts outside. This allows for a cheat strategy of opening door, shooting with everyone, closing again.

Desired:

Aliens be capable of opening Ufo doors themselves when there are xenonauts standing outside, perhaps also shoot the xenonauts, close the door.

And maybe xenonauts be incapable of opening an alien ufo door which probably has some quantum security mechanism?, then you have to blast through them.

This seems partly true, do you mean when you are sat right next to the door.

I had a frightening few turns in an Andron Medium base when I had about 7 guys moving up a corridor apparently safe and as they got to the corner over the next 3 turns 5 Andron guards came charging out a door next to it. Many Shuvs and Zuuls knew what it was to be roasted in the depths of the Slor that day.

[Belmakor]

Observed:

On the new terror map, Casean with plasma rifle was on my flank (within sight) and I had 3 guys there in a bad way, 1 on less than 50% health, one who had been mind controlled. Uninjured Alien ran away and ended up being the last AI alive, hiding in the corner of a convenience store.

Desired:

If Aliens are engaged in Combat and there are other Aliens (even passive ones) within sight of the combat they should make an effort to move forwards and engage. Just now it seems that if they don't have line of sight to shoot they will just run around doing their own thing or sit still.

[lemm]

^ Aye.

The aliens need to make coordinated pushes and retreats.

They should also make a concerted effort to flank the Xenonaut force.

[Chris]

Some aliens on terror missions are deliberately passive. If some of them don't act that way, as soon as one of the aliens spots your dropship they all sprint over together and the terror site turns into one massive battle around the dropship (with no exploration of the map needed, just enough heavy weapons to take down the alien zerg rush).

[Skitso]

I'm generally really pleased in the state the AI is now. Three things I'd still like to get addressed:

-Sometimes they still reserve TU's for reaction even if they have LOS to xenonauts.

-Turning automatically towards nearest xenonaut even if not visible is a severe AI hack that needs to go! Also make aliens less prone to make 360's to check flanking units. -> more fun game when it's possible to flank and surprise enemies.

-And third, I hope you get the aliens using higher ground working.

Edited March 16, 2014 by Skitso

[StellarRat]

I think the 360 check is OK. That's what I do with my own troops. The facing thing definitely needs to be fixed though. It should be possible to sneak around behind an alien if there is something blocking their line of sight. I also really wish the "hear/see" through walls thing could be fixed. It really takes the fun out trying to sneak on aliens in general.

[Caaygun]

This seems partly true, do you mean when you are sat right next to the door.

I had a frightening few turns in an Andron Medium base when I had about 7 guys moving up a corridor apparently safe and as they got to the corner over the next 3 turns 5 Andron guards came charging out a door next to it. Many Shuvs and Zuuls knew what it was to be roasted in the depths of the Slor that day.

I mean, aliens are incapable of opening a door if you have occupied all tiles adjacent to it with your men. I think they can't do the "open only" action you can do, but aliens can only do "open-move" to the tile just on the other side of the door. Aliens want to move into the corridor behind the door, but since you occupy it with your men, they can't and more often than not they just duck on the other side of the door without opening it. Next turn you open the door, MG them, perhaps even two of them simultaneously with all firepower, close the door back, end turn and wait for the next wave to come in. So if you put 3 men adjacent to a base door, its effectively blocked for alien passage.

[Belmakor]

Some aliens on terror missions are deliberately passive. If some of them don't act that way, as soon as one of the aliens spots your dropship they all sprint over together and the terror site turns into one massive battle around the dropship (with no exploration of the map needed, just enough heavy weapons to take down the alien zerg rush).

That would be annoying, truly (well the odd occasion would be rather unexpected and enjoyable!).

Maybe passive aliens should have lower shot % thresholds so that they tend to fire more from further back? That way they are not going to run away or sit around but might contribute a little (read: healthily) without crowding the dropship?

AND

Could you have a small chance each Alien turn of a passive alien becoming aggressive. Perhaps this chance would increase the higher the available shot chances. This would allow the AI two emergent game-plays;

* an Alien that has suddenly come into close combat has a high chance of behaving aggressively (i.e. spending all TU's on shooting). Whereas now they might take a pot shot then run away only to be shot in the back on the Xenonaut turn.

* occasionally a passive alien sitting at the edge of the current battle might decide to wade in unexpectedly.

[Chris]

Passive-aggressive aliens? An interesting idea.

[AvistTorch]

I mean, aliens are incapable of opening a door if you have occupied all tiles adjacent to it with your men. I think they can't do the "open only" action you can do, but aliens can only do "open-move" to the tile just on the other side of the door. Aliens want to move into the corridor behind the door, but since you occupy it with your men, they can't and more often than not they just duck on the other side of the door without opening it. Next turn you open the door, MG them, perhaps even two of them simultaneously with all firepower, close the door back, end turn and wait for the next wave to come in. So if you put 3 men adjacent to a base door, its effectively blocked for alien passage.

I haven't yet brought a game to the point where this becomes an issue, but I've seen this in MetalCanyon's LP. I'm not sure if this is still a problem, but if it is, it's something I'd also really like to see fixed.

[Skitso]

I'm not quite sure if this is reported or not, but the aliens can't open a door other than by walking through it so if I place a Xenonaut behind a door, aliens can't do anything about it and just wait on the other side to be killed on the next turn. This makes the "open the door - shoot - close the door" tactic a bit too powerful when breaching an ufo.

[Kirill Selivanov]

Strange Anti-crowding bug in terror missions (22 bild stable)

about 15 androns stay tuned. they doesn't come closer to teammates (3-5 squares between) - so only 3-4 first come to me, others - are waiting their time to come-)

Besides of that - the terror maps are to small and that 15 (or more) androns come to me at 3-4 turn all!

[Kirill Selivanov]

AI in the big many-flour ships (guards) doesn't come normally in the first flour to defend it.

Example

Cruiser

if i oben back doors to the wings and come there - none comes to 1st flour.

if i move in the central door - they come down, but all go to the central room (they move to the wings if there no other way to central room)

Else

Dropship\Corvete

Guards doesn't stay in first flour if my troops moveout from the first flour of the ship - they move all again to the second flour

plus if there doesnt checkes special placec in corvete (2 closed to the door central squares besided boxes) - they just stay and doesn't fire)

Else

Carrier

the AI guards doesn't come to 1rst flour at all. I puted round the teleport 3[ soldiers and move one to second - to provoke tham. so they came(1 after another) - but all died faster than TUS of my soldiers ended (Carrier crew must be upped!!! there much more guards of the officer than in all other ship!)

So no guards in the first flour when the storm begins at all! its pity! How challengable the large scout - and how strange to make box-fires when they even doesn't come to non central rooms.(may be in just preset corpses)

plus strange bug - i've got an alive caesian leader from sibilian carrier (none was seen there at all). please check that.

And sometimes strange guards close to the central doors appear. Are they guards or thay are doesn't moved out field warriors?

[Talonhawk]

Just playing through the latest Version,

for some reason im not getting any other aliens other then Ceasen's Im up to UFO 150 every ship from small to massive but its always 3 aliens only even on Terror missions. I can contuine on indefinately I have reasearched everything but the game wont play forward with other aliens.

[Talonhawk]

Just playing through the latest Version,

for some reason im not getting any other aliens other then Ceasen's Im up to UFO 150 every ship from small to massive but its always 3 aliens only even on Terror missions. I can contuine on indefinately I have reasearched everything but the game wont play forward with other aliens.

Quick updte to this, I just updated the game and this problem has gone away, just a wierd one.