The Official AI Topic.

[shadowofchaos]

Did you test that more times? 2 is a low sample size. It would definitely tell us something if Gangrel always attacked from that square in that circumstance. At the very least, less RNG than expected.

You have no idea how many times I tried Gangrel to attack Olivia at 1 range.

Which is why I was confused when someone said they'd eat a counter at 1 range if there's a positive terrain tile next to you. The only time I've seen Gangrel attack at 1 range, was if you were swarmed with enemies and all the 2 range'd spots were taken.

Even trapping him with 3 paired up people and that chest. He attacked both Annie and Sumia, but never Olivia. And this is loading the same Suspend/Bookmark save with the save dongle, so the RNG is THE SAME in every instance just like a casual mode save.

Edited June 17, 2013 by shadowofchaos

[XeKr]

Related to its ability to plan ahead moves, consider this scenario:

One of your units is in range of multiple enemies, but there are less spots to attack that unit from than there are enemies in range. However, some of these enemies are likely/guaranteed to survive your unit's retaliation, while some of them are likely/guaranteed to die. If these enemies could potentially kill your unit given more attacks than the bulky enemies can provide, it will purposely suicide the less durable enemies on your unit just to damage it enough to kill.

Hmmm...I can think of an example where the AI didn't plan that far ahead. In my recent Lunatic C2 clear, my Avatar could have died if 2 Soldiers suicided into her first, then was attacked by a Barbarian. Instead, the Barbarian attacked Chrom and the Soldiers ran into Avatar afterwards.

It "seems" that the enemy order is set, as in first Barbs move, then Myrms, then Soldiers or something.

You have no idea how many times I tried Gangrel to attack Olivia at 1 range.

Which is why I was confused when someone said they'd eat a counter at 1 range if there's a positive terrain tile next to you. The only time I've seen Gangrel attack at 1 range, was if you were swarmed with enemies and all the 2 range'd spots were taken.

Even trapping him with 3 paired up people and that chest. He attacked both Annie and Sumia, but never Olivia. And this is loading the same Suspend/Bookmark save with the save dongle, so the RNG is THE SAME in every instance just like a casual mode save.

Wait, maybe I'm misunderstanding, but if the RNG is the same, won't obviously the same thing happen every time? I think people have reported the inability of Bookmarks to rig growths and such.

When I'm talking about "randomness", I'm referring to reseting the chapter completely (which seems to change the RNG seed) or just end turn again and again (as you did twice in that video).

Somewhat simple evidence for random movements: Pick any map. End your turn immediately with all your units out of range. Note enemy positions. Reset and repeat. I just did it a few times in a Challenge in Aversa's map. It really seems pathing is random (unless somehow the enemy skill distribution is affecting its AI).

Also, if Gangrel is somehow choosing between Annie and Sumia, that also suggests an RNG component in the AI deciding who to attack.

EDIT: I'm doing a little testing and I'm getting results consistent with yours so far wrt to the terrain issue. Enemies appear to prefer avoiding counters over terrain in all the various cases I tested with strong/weak or enemy/player units. Enemies that attack at 2 range to avoid a counter generally do not move to a different tile to attack after each turn, they just stay put.

Hmm...maybe it was in Tiki's chapter or something, with notoriously weird AI.

Edited June 17, 2013 by XeKr

[BlueFire]

It "seems" that the enemy order is set, as in first Barbs move, then Myrms, then Soldiers or something.

I've always assumed the AI moved in order of unit listing in FE games, after factoring in various priorities.

[shadowofchaos]

Wait, maybe I'm misunderstanding, but if the RNG is the same, won't obviously the same thing happen every time? I think people have reported the inability of Bookmarks to rig growths and such.

He attacks Sumia or Annie. I also made another bookmark after that initial attack. It's one of the two at close counterattack range. Never Olivia.

Though I didn't equip Olivia with anything other than a Brave Sword.

[Donnel]

Might be a challenge for you guys.

Is it possible to find out the pattern of 'check' from the A* algo?

Maybe it follows the pattern of Bottom, Left, Top then right, but I'm not sure.

The idea is to find out the priority in which the enemy attack first if 2 identical MU are placed in equal distance but in range of the enemy.

If both have the same def/res, what is the next stats for 'tiebreaking'?

All this are 'additional info', not of necessary importance, but are interesting to know.

[Interceptor]

Worth noting that the two barbarians near the bridge in Paralogue 2, will actually attack your units rather than the village. Every other barbarian has the horse-blinder behavior, except these particular two. They actually appear to be tied to the units north of your starting position, and will stand as still as statues until you either aggro them or the boss moves.

EDIT: this is Lunatic+

Edited June 17, 2013 by Interceptor

[1% critted]

Worth noting that the two barbarians near the bridge in Paralogue 2, will actually attack your units rather than the village. Every other barbarian has the horse-blinder behavior, except these particular two. They actually appear to be tied to the units north of your starting position, and will stand as still as statues until you either aggro them or the boss moves.

EDIT: this is Lunatic+

Oh, I forgot about those two. Since I deliberately aggro them towards an unit in a forest on the first turn, I forget that they are actually gunning for you.

Still, nice post. And it works on Regular Lunatic too.

[darkkfan]

The enemy order being set seems to make sense generally, since it wouldn't contradict the whole move out of the way so you can attack thing like in your Ch 5 example. But I think that if the order is set it will change if the AI can kill someone since on Ch 12 of Luna+ I was trying to wall up in the center and I found that the paladin will kill Lissa first if he has pass, but if he can't then he will wait for the two cavs around him to suicide on Chrom first to ensure that he can kill Chrom.

[Kuroi Tsubasa Tenshi]

I can confirm that I've encountered the "enemy with 1-2 range weapon will attack at one range if the terrain is a favourable tile", although I've seen this behaviour with units in general, so it's not a Counter script thing (I've had this happen to me about a half dozen times with pillars on various runs on chapter 17).

This seems work both ways, though. I only have one sample here, but during chapter 21 of my last run, a tome-wielding Avatar was facing an Assassin who had both a bow and a sword. The Assassin had Counter and in my experience, was very likely to use his sword, but I had to kill another priority target (can't remember what, but not really important), so I made the kill ending with Avatar being 2 tiles away from some Stairs. The Assassin opted to jump on the Stairs and fire his bow.

Sometimes enemies will fight at one range with 1-2 weapons for no discernible reason too. I encounter a Dark Mage in chapter 19 and a Sage in Yarne's Paralogue where there were several spaces around Avatar open that would allow them to fight at 2 range, but they decided to take her on at one range. I have no idea why, as no one was body blocking them, there was no advantageous terrain around and at least in the Sage's case, the rest of his team had already acted. Both had Counter and caused me serious problems (the Dark Mage instance getting her killed and the Sage instance leaving her with single digit HP). The whole reason I even got caught with my pants down like that is I assumed they would attack at 2 range.

[Interceptor]

Sometimes enemies will fight at one range with 1-2 weapons for no discernible reason too. I encounter a Dark Mage in chapter 19 and a Sage in Yarne's Paralogue where there were several spaces around Avatar open that would allow them to fight at 2 range, but they decided to take her on at one range. I have no idea why, as no one was body blocking them, there was no advantageous terrain around and at least in the Sage's case, the rest of his team had already acted. Both had Counter and caused me serious problems (the Dark Mage instance getting her killed and the Sage instance leaving her with single digit HP). The whole reason I even got caught with my pants down like that is I assumed they would attack at 2 range.

At least in the DM's case, I'd venture a guess that perhaps Hex had something to do with it. Maybe Focus for the Sage?

[shadowofchaos]

When everyone has 1 ranged weapons, unlike how smart the AI is when moving mooks away so they can kill healers... they won't move healers out of the way to get at a bow user.

[Donnel]

When everyone has 1 ranged weapons, unlike how smart the AI is when moving mooks away so they can kill healers... they won't move healers out of the way to get at a bow user.

woah! That's amazing trick you did there. How do you get them to 'screw themselves' like this?

[Kuroi Tsubasa Tenshi]

At least in the DM's case, I'd venture a guess that perhaps Hex had something to do with it. Maybe Focus for the Sage?

Hmmm, yeah, I'd say it's more than likely you're right.

[shadowofchaos]

woah! That's amazing trick you did there. How do you get them to 'screw themselves' like this?

When someone is on the cliff in that map and they are the only ones reachable via 2 ranged weapons [as in all the fliers are also dead]... the "one ranged units" will not move.

I rescue staved Anna back down... and well...

It wasn't intentional. Lachesis/Raquesis just HAPPENED to move next to a nearly dead Hardin to use Recover on him... right in front of Anna. Hardin attacked Anna from two range with his Gradivus... and Libera/Libra happened to Dual Attack twice with his tome. And he was the last one with a two ranged weapon.

[1% critted]

I can confirm that I've encountered the "enemy with 1-2 range weapon will attack at one range if the terrain is a favourable tile", although I've seen this behaviour with units in general, so it's not a Counter script thing (I've had this happen to me about a half dozen times with pillars on various runs on chapter 17).

This seems work both ways, though. I only have one sample here, but during chapter 21 of my last run, a tome-wielding Avatar was facing an Assassin who had both a bow and a sword. The Assassin had Counter and in my experience, was very likely to use his sword, but I had to kill another priority target (can't remember what, but not really important), so I made the kill ending with Avatar being 2 tiles away from some Stairs. The Assassin opted to jump on the Stairs and fire his bow.

Sometimes enemies will fight at one range with 1-2 weapons for no discernible reason too. I encounter a Dark Mage in chapter 19 and a Sage in Yarne's Paralogue where there were several spaces around Avatar open that would allow them to fight at 2 range, but they decided to take her on at one range. I have no idea why, as no one was body blocking them, there was no advantageous terrain around and at least in the Sage's case, the rest of his team had already acted. Both had Counter and caused me serious problems (the Dark Mage instance getting her killed and the Sage instance leaving her with single digit HP). The whole reason I even got caught with my pants down like that is I assumed they would attack at 2 range.

Doesn't Silver Bow have more Might than Silver sword?

[Tamanoir]

Doesn't Silver Bow have more Might than Silver sword?

Bows are as strong as Lance, so yes. 2 more Might to be exact.

[1% critted]

Then the Assassin went for the bow attack because it would have done more damage.

[Kuroi Tsubasa Tenshi]

Silver Swords have 10 more hit, though. I believe they typically place a pretty heavy emphasis on making sure they can land the blow in the first place. I've seen Bow Knights and Assasins go into melee rather often.

[Interceptor]

Just to add to this, when there is no weapon triangle involved, keep in mind the weapon rank bonuses. Swords are +3mt at A-rank, and Bows are +2mt/+5hit. So the real difference between Silver Sword/Bow in the hands of someone with both capped, is +1mt in favor of the Bow, and +5 HIT for the Sword.

[1% critted]

If a both attacks reach 100%, they should go for the one with higher might.

[Kuroi Tsubasa Tenshi]

Just to add to this, when there is no weapon triangle involved, keep in mind the weapon rank bonuses. Swords are +3mt at A-rank, and Bows are +2mt/+5hit. So the real difference between Silver Sword/Bow in the hands of someone with both capped, is +1mt in favor of the Bow, and +5 HIT for the Sword.

Oh, yeah. 1mt and 10 avoid vs 5 hit in this case, then.

If a both attacks reach 100%, they should go for the one with higher might.

I'm pretty sure the attack missed, so it wasn't at 100.

[1% critted]

Oh I missed the part where it missed.

[Kuroi Tsubasa Tenshi]

Oh I missed the part where it missed.

Nah, you didn't. I've just been going into more detail as it becomes relevant. Avatar paired with Chrom still has a pretty good avoid at that point in the game, even if its reliability is starting to drop rather rapidly.

[1% critted]

Yeah, it's at that point that dodge tanks stop being all that useful and true defense or life drain becomes necessary.

The only thing that can be reliably dodged are berserkers.

[1% critted]

Updated the OP. I'll need someone to tell me when the chapter 16 units move, since I play that chapter in such an aggresive way every time that I have no Idea how they move. All I know is that they are aggrod when in range.