Huge problem: passive aliens inside ufo's

[StellarRat]

An AI that does whatever is needed to win is often an AI that cheats i.e it knows far more about what you're doing than you can know about what it's doing and/or given even more obvious advantage like biased dice rolls, etc...

[Tulx]

The problem with "always do it's best to win and throw any other consideration out of the window" is that overtime it becomes predictable, and makes easier for the player to counter. Occasionally taking the less statistically optimal approach will surprise the player, who cannot rely on the alien doing what it is "supposed" to. A good example is the aliens sometimes charging out of the UFO. The best thing to do would be to have them all camping, covering the door. But the possibility they might counter attack, even though it is more risky and not the optimal strategy, keeps the player on his toes and makes it harder

I don't think either that aliens behavior should be static and I think that making the AI somewhat unpredictable is a "win at all costs scenario". Because it is impossible to code an adapting/learning AI that plays against human players strategy depending on the situation. I think that adding random situations like charging through the door occasionally is the correct behavior. To conclude: I'd like to see an AI that given the limitations of it, is the best that it can be and isn't dumbed down to specifically make the game easier for the human player.

It would be awesome even if some very limited team behavior could be implemented. Ie. one alien opens the outer UFO door and another one chucks a grenade or fires from behind a cover. That would atleast simulate intelligence somewhat. After all, human player can constantly use the game mechanics to it's advantage (opening and closing doors won't trigger reaction fire), why shouldn't the AI? (besides the obvious "can't be done because too long turn times/impossible/engine limitations").

Remember I'm not criticising anybody sorry if I appear too harsh.

Edit: Actually when AI chooses "the best statistically optimal approach" it won't become predictable. It would become super good starting to shuffle it's strategies like mad to flank, backtrack behind players position etc. A statistically best decision isn't the statistically best decision anymore when repated enough times, if you get what I mean.

Xenonauts AI system that is imperfect like it is cannot realise that and only does what it thinks is statistically the best decision when asked to do that.

Edited June 22, 2014 by Tulx

[Tulx]

An AI that does whatever is needed to win is often an AI that cheats i.e it knows far more about what you're doing than you can know about what it's doing and/or given even more obvious advantage like biased dice rolls, etc...

An AI that is successful at actually winning might utilize full map vision. An AI that attempts to win at whatever costs given the same rules like human player might not be that good, sure, but it still tries it's best - and that's what I meant. I didn't mean by "whatever neccessary" the AI should teleport next to the human player soldiers at the first turn and insta kill them (very blatant example of "cheating" but goes to the same category as full map vision).

[kabill]

This issue will probably be fixed in the next hotfix/patch. I uploaded a patch yesterday evening.

It should also deal with the infamous "I-can-block-a-door-with-a-unit" bug.

Cool, glad it could be solved.

@Kabill

On debugging:

I saw in the save(s) you provided that you used the editor to setup several situations for the AI. I want to warn you that using the editor breaks the game in a lot of places. Especially tweaking the unit values will break a lot of AI effect calculations. This isn't a bug in the AI, but in the Editor in how it incorrectly sets values sometimes.

One example is where you placed a unit with a modded high HP value next to the entrance. The Editor didn't adjust the maxHP correctly and set it internally to a negative value, this in turn resulted in the AI thinking that its effects would be positive for the Xenonaut, hence it not shooting.

I'd actually noticed that specific issue and assumed it was down to the editor. I'm not certain it was causing the aliens to act how they were in terms of their movement, though.

Foe what it's worth, when debugging using the editor I normally only edit the AP value so that I can rush to the UFO. Once I'm there, I'll test things normally (unless I'm dashing to a particular part of the UFO, anyway).

On the moving issue:

There are as many opinions as there are people with regards to this. First it was a problem that AI units were crouched in defensive positions and wouldn't move, now it's that units in the UFO move too much. For this reason I've actually made it easy to disable that; just zero out the ProbabilisticSearch value in aiprops.xml.

I don't think it's the moving per se that is a problem so much as the AI moving backwards and forwards for no reason. If it was moving somewhere useful, like patrolling the ship, that wouldn't be an issue. But if they're just moving to the tile next to them and back it's a waste.

Edited June 22, 2014 by Gauddlike
Fixed broken quote box

[Ragnarok]

I feel like the fixed move-5 per turn is certainly a considerable issue.

By accident i had sight into an Ufo. In the opening room were 2 Caessins. They couldnt see me, but i could see them and so i saw how they moved exactly 5 tiles back and worth, wasting time Points leaving cover, opening themselves to reaction fire.

[TacticalDragon]

Hehe, yeah it is.

Once things are settled down and I have some time to burn, I might make an AI mod aimed at above-insane players.

Gijs, I have some experience with melee units programation, if you want I can send you the model that I use for some units.

A small question, until update 1.06 my aliens are unable to open the door if is occupied by xenonauts at the other side... something is wrong?

[tonberrytoby]

That pacing around can be fairly confusing. I have had aliens knock themselves out by walking from a save place through fire or KO-Gas.

While I had nobody in that room.

[kabill]

For this reason I've actually made it easy to disable that; just zero out the ProbabilisticSearch value in aiprops.xml.

Is this supposed to be in the current build? It seemed from your comment at the top of your post that you'd already released the patch, but I tried this and it doesn't work. Have I misunderstood and it's actually just been readied for the next patch?

[Gijs-Jan]

It will be in the next build.

[Skitso]

Any idea when that would be?

[Gijs-Jan]

It should be in the new patch; and that should include a fix for AI not using doors if you block them. (which apparently is also in OpenXCOM, hilariously enough)

[Skitso]

Ah, splendid! Can't wait to have time to start a new game then! Thanks GJ!

[Chaos Blade]

I noticed this as well, while it is reasonable for the commanders to camp up in the bridge and set up the last line of defense and some could be argued that the troops inside the ufo should reasonably fort up, they are just too passive, no counter attacks to xenonauts camping just outside the door, no attempts either only psions do their stuff and that is mostly annoying.

I mean, I can understand them being somewhat passive in some circumstances, but they are entirely too passive, letting us take the whole initiative for the ufo assault. I think I only had one counterattack while I was assaulting a cesarean LST and that was while I had secured the ground floor.

Still it is good to know that this will be looked into by the pros!

Edited June 26, 2014 by Chaos Blade
missing a line of text

[kabill]

So, I had a tiny little play around with the new v1.07 AI.

Opening blocked doors definitely works. However, it appears like AI units will always open doors when they move close to them now, and can open them at a distance (i.e. it triggers when they're a tile away from the tile containing the door). Is this intentional?

AI still wanders around on its turn. I assume this is intended. However, I tried changing the the probabilistic search values to 0 and that continued to happen. Is this supposed to be the case, or have I misunderstood (again) what that was supposed to effect?

Haven't had chance to check the not-attacking issue yet.

[junker154]

I noticed this aswell. Apparently during crash missions the AI decides to let some units out for scouting and the rest stays in the ship, preparing for the last stand. It's really awesome for the first few times but I think that it gets tedious really fast.

After killing few aliens outside you always kind of know that the last ones are hunkered down in the ship. A bit more variety in their behaviour would be neat. Also having multiple entries in a ship would neat (although the biggest ship that I downed was a corvette). Storming an ufo is always a difficult but tedious task.

It would definitely spice up the gameplay a bit if not every alien is in the ship. In the old Xcom games, the AI had a tendency to go out a lot more.

A positive aspect is that the alien hunt for the last remaining enemy is far shorter, usually you know that the last alien is hidden in the downed ship.

[Hokum]

I noticed this as well, while it is reasonable for the commanders to camp up in the bridge and set up the last line of defense and some could be argued that the troops inside the ufo should reasonably fort up, they are just too passive, no counter attacks to xenonauts camping just outside the door, no attempts either only psions do their stuff and that is mostly annoying.

I mean, I can understand them being somewhat passive in some circumstances, but they are entirely too passive, letting us take the whole initiative for the ufo assault. I think I only had one counterattack while I was assaulting a cesarean LST and that was while I had secured the ground floor.

Still it is good to know that this will be looked into by the pros!

I've been lurking here for 4 years, and started to play with v 1.0. The game is near perfect in every aspect. However, the AI-passivity, as Chaos Blade described it perfectly, is so bad it made me stop playing. Please fix this!

Also, thank you for making such a great game.

edit: I have to add that I mainly encountered sebillians and caeseans until now (and my first reapers), and at least the sebs like hiding a lot. Nonetheless, I think the game would be more fun if aliens were more aggressive and sought you out, as in Jagged Alliance 2 for example.

Edited June 27, 2014 by Hokum

[kabill]

I've been lurking here for 4 years, and started to play with v 1.0. The game is near perfect in every aspect. However, the AI-passivity, as Chaos Blade described it perfectly, is so bad it made me stop playing. Please fix this!

Also, thank you for making such a great game.

As I wrote up thread, I think I've found a (partial) 'fix' for this.

The trouble seems to be that the AI is reserving TUs for reaction fire, hence it limits its movement significantly to ensure it has TUs available. It's possible to turn this off, which seems to make the aliens move around much more in the UFOs. However, as the aliens tend to mill around on their turn anyway, it also basically means that they waste all their TUs and therefore never have anything available for reaction fire.

If you want to try it, go to aiprops.xml and find the "defensive" and "command" AI overrides (near the top, before the alien lists).

Replace those two entries with the following:

			<Defensive>			<PathingMechanics 					FloorPreference = "0.25"					/>				<!-- Ensure that the Defensive AI searches around the UFO, and doesn't just blindly search for enemies. -->			<Pathing 					Sight="2"					Cover="-15"					ShotPotential="-26"					EnemyInfluence="3"					AlliedInfluence="-3"					EnemyLOS="4"					Trepidation="10"					ProbabilisticSearch="-6"					Goal="-30" />				<Decision 					MinimumAccuracy = "0.15"							MinimumAccuracyGrenade = "0.15" />			<PathingMechanics 					FloorPreference = "0.25"			                CautiousDistance = "0"					/>			</Defensive>		<Command>			<!-- Ensure that the Defensive AI searches around the UFO, and doesn't just blindly search for enemies. -->			<Pathing 					Sight="4"					Cover="-1"					Ambush="-25"					ShotPotential="-26"					EnemyInfluence="1"					AlliedInfluence="-0.25"					EnemyLOS="4"					Trepidation="4"					ProbabilisticSearch="-3"					Goal="-60" />				<Decision 					MinimumAccuracy = "0.15"							MinimumAccuracyGrenade = "0.15"					ChanceForExpansionFromGoalTiles = "0.6" />			<PathingMechanics 			                CautiousDistance = "0"					/>		</Command>

[Skitso]

I've had lots of this lately: sebillian runs towards my unit, maybe 2-3 tiles away and instead of shooting him, reserves it's TU's. Happens multiple times in every GC.

Aliens inside ufo's are much better though!

[kabill]

I've had lots of this lately: sebillian runs towards my unit, maybe 2-3 tiles away and instead of shooting him, reserves it's TU's. Happens multiple times in every GC.

Aliens inside ufo's are much better though!

I need to do an experiment turning off all of the minimum shot chance thresholds. From what I can tell from testing, the not-shooting thing does seem to be related to that.

For example, yesterday doing a quick test I had a Caesan move towards one of my soldiers who was crouching behind a wall. It stopped it's move after 4-5 tiles and did nothing. As an experiment, I uncrouched the soldier and didn't do anything else. On the alien's turn, it shot without moving (i.e from where it should have shot from last turn).

What appears to be the case, then, is that the AI can't (reliably) override whatever is stopping it from moving far enough to get a good shot. So it moves a bit, can't shoot due to the accuracy threshold, and holds position instead (rather than moving to hide or moving further for close-range bonuses or whatever). Might not be, mind, but this is my working hypothesis at the moment. As I say, needs testing to see if it makes a difference though.

[Skitso]

I'm not getting the wraiths. Shouldn't they be really tough enemies and offer unique challenges, teleporting around killing your troops? They just teleport next to my units to be shot to shreds. The ai could really use some tweaking there. Funnily the teleport animation is displayed even outside of players FoV, so when one teleports in your flank, you see it even if you shouldn't and the surprise factor is gone.

Edited June 29, 2014 by Skitso

[KevinHann]

I am certain Wraith teleport should not show any animation to the player unless the alien is visible, and there shouldn't be any sound with it. It would also help if Wraiths don't move after teleporting but still have full reaction fire available in the next move.

[Fucille]

I need to do an experiment turning off all of the minimum shot chance thresholds. From what I can tell from testing, the not-shooting thing does seem to be related to that.

For example, yesterday doing a quick test I had a Caesan move towards one of my soldiers who was crouching behind a wall. It stopped it's move after 4-5 tiles and did nothing. As an experiment, I uncrouched the soldier and didn't do anything else. On the alien's turn, it shot without moving (i.e from where it should have shot from last turn).

What appears to be the case, then, is that the AI can't (reliably) override whatever is stopping it from moving far enough to get a good shot. So it moves a bit, can't shoot due to the accuracy threshold, and holds position instead (rather than moving to hide or moving further for close-range bonuses or whatever). Might not be, mind, but this is my working hypothesis at the moment. As I say, needs testing to see if it makes a difference though.

You've just made me turn all the alien minimum accuracy values down to 0.15 from 0.35. I'll see how it works!

EDIT: Wow, what a result! The aliens are WAY more aggressive now! Not as many of their shots land, but they take so many shots that the sheer volume ensures I take wounds if I just rush around the map without a cohesive group. Would HIGHLY recommend!

Edited June 30, 2014 by Fucille

[kabill]

You've just made me turn all the alien minimum accuracy values down to 0.15 from 0.35. I'll see how it works!

EDIT: Wow, what a result! The aliens are WAY more aggressive now! Not as many of their shots land, but they take so many shots that the sheer volume ensures I take wounds if I just rush around the map without a cohesive group. Would HIGHLY recommend!

Cool, that's useful to know.

Thinking about it, 35% minimum is actually quite high. If you're behind 50% cover, when aliens have a base accuracy of ~60, then they shouldn't really be shooting (60*50% shot type = 30*50% cover = 15*125% generic alien attack increase = ~19% to hit).

If the short-range bonus extended out further (which is now moddable, thanks Solver!), it wouldn't be so bad because the aliens could close in a little and get an accuracy buff. But to get bonuses to hit you need to more or less be in you're target's face, which is probably what's resulting in death-charges or milling around not doing anything.

[andreasg]

Sounds like there's some potential here.

While I don't think that the AI should be rushing the dropship, I do think that the AI is too passive and predictable at the moment.

One could perhaps also randomise the number of different roles of aliens. Anyhow, there seems to be a general lack of good AI mods.

I've tried to steal a few things from XNT and this thread to put into my own AI config file, but I'm still not entirely happy. I'm not entirely sure how some of the properties work exactly (If I want passive aliens to be less passive, should I decrease or increase the goal value?)

[FireStorm1010]

Agreed with op, to add i think the AI is much much better outside of ufos. I had recently my first terror site and the aliens really impressed me in a good way, moving all time, being agressive, had lots of fun.In ufos tough its true they tend to sit in place (altough i had recently a a few occasions the aliens actually attacked me inside of ufo moving through doors, not waiting for my assault)