AI

Hi,

A friend of mine and I really enjoy playing the eastern front mod. Sure, we are occasional playsers and, hence, not professionals, but we are improving. From our experience, the step from "easy" to "normal" is a significant one. Often, it is really frustrating that we seem to loose ALWAYS when units of equal strength meet on the battlefield (especially on maps crowded with buildings). When comparing "easy" and "normal", we got the impression that for "normal" the probability values are changed significantly to our disadvantage. It is always a matter of tactics of course. However, we have the general impression that changing to difficulty "normal" means weakening our units to class "cannon fodder".

Hence, our question is: could somebody please give a basic characterization of the different AI steps (and the pertinent major changes)?

There are only two persons that know this!

robo and jojo!

Walki wrote:
There are only two persons that know this!

robo and jojo!

Presenting to you, Eastern Front AI Reality Show!!!

To the question, I believe easy has less health or income, but not sure.
Better wait for the coder.

(P.S.: Though seriously, you guys need to make that kind of show... :P )

Here's my take.

Easy: AI collects .75 of the resources that the player collects. AI uses a basic Build order in the Static (preprogrammed) phase of the game.
Normal: AI and Player are on an equal footing for resource aquisition. AI uses a basic Build order- Static.
Hard: AI Collects 1.25 resources. "AI personalities" are selected at Game Start, in Addition to Static Build Order other Build orders are added to the mix. Example "Wehr Heavy Engineer" personality is geared to Set up Wher for Fast Vehicle Start. In the Static phase It will build 2 Pios and send them out to cap and OP two Fuel Points. (This is a simplification of the "Heavy Engineer" Static Build Order - Dont want to let too many cat's out of the bag.
Expert: AI collects 1.5  resources and can be given more complex AI personalities.

Different tweaks are (can be) granted to AI Tactics, AI Unit selection, etc; that apply to the different Hardness levels as well.

If you can Read LUA programming language, (SCAR is a subset of Lua), You can determine many aspects of CoH/EF play, without recourse to Corsix. I don't think you can acess unit stats without Corsix though.

Are probability values affected as well? It feels like our units hit less frequently whereas the AI units are more likely to hit our units.

We meet many situations where our units seem to be overwhelmed too easily. For instance, it happens quite often that a anti-tank unit (facing a Puma) is lost by some shots without hitting the vehicle.

From my point of view, losses should feel like "the opponent tactics was superior to my one" or "I still have to train a lot". That is okay of course and motivates us to play again. In the eastern front mod, however, losses against "normal" additionally feel like "the opponent seems to know everything", "my units are failures" or "I somehow feel betrayed".

I suppose that other good (but occasional) players of the mod may feel the same way.

AI combat power is adjusted in vCoH and they get a resource bonus. In EF, the AI is changed so combat is always on par but they get a larger resource bonus than vCoH.

The Show  ;D

If you ever programmed AI for some simple games like tic-tac-toe, connect4 or complicated game like chess you will know what am talking about, but i will try to explain this as simple as possible.

In every game AI thinks or evaluates, in board games like connect4 difficulty is determined with step (how far will AI look).
In connect4 if step is 3 then AI will calculate 3 moves from current move "to the future". Or simpler one his move one yours move then again one his move and with results AI will calculate how much chances that moves gives him to win. With these simple games it is easy to make AI unbeatable.

Evaluation is method that usually calculates what is best move for AI or simpler what move gives AI more chances to win that is in case of board games. On board games there are no dependencies on resources or something, in CoH you have res etc..

Back to the Show ;D
In CoH evaluation is method that calculates what is best unit to produce to counter enemy units which also means more chances to win.
For example if you are facing Axis and you build sniper sooner or later you will see motocycle/shwimwagen on the field that is trying hunt your sniper. Or jeep if you are facing american AI.

Some examples how AI counters maybe it will help you to defeat AI: 
- snipers with light vehicles(jeep/motorcyle/swimm)
- HMG with snipers
- rifleman (infantry) with snipers or hmg(calculates what is better)
- defensive buildings (bunkers etc) with mortars
- ATG with mortars or snipers

Step from easy to normal is huge cuz easy AI does not calculate anything he just makes random units.
AFAIK only Hard and Expert AI have res bonuses + Expert AI calculates with better precision, if normal AI would calculate with expert precision then it would be more hard AI then normal AI ;).

Simple: your units are overwhelmed easily cuz evaluation, AI makes units that easy counter your units.
AI knows all units you have and then calculates what is best unit to counter your units and produces one of top 5 best units in calculations exceptions is for expert he will always produce best unit.

Losing AT with puma is AI tactic to avoid as much as possible AT ;). Try to guard AT with something rifleman maybe with stickies. Also Wehrmacht AI is the smartest one in game, normal Wehr seems like Hard amer sometimes.

I usually play vs normal or hard and i play like a noob.
When i started to play CoH normal AI was so hard to me (i never play easy cuz i know easy in most games does not calculate), easiest way to kill normal AI for me was to deny him fuel so he does not have more fuel then me.

Like Otto said personalities are also changed with difficulty levels, hard is more aggressive, attacks more often with more units etc.
But easy is easy enough without calculating it does not need 0.75 res. Easy IIRC will not attack until 3-4 mins of game are passed -> i need to check this.

If in coh i would use your "moves" and your res in calculations then AI would be a way to smart and unbeatable.
This does not affect unbeatable expert AI with res bonuses, expert is hard to beat cuz res bonuses and better calculations.

I hope I explained simple as possible ;).

QuoteI suppose that other good (but occasional) players of the mod may feel the same way.

Cuz players don't think in a good way. Some strategies that you find over the internet will never work vs AI, cuz AI knows what units you have ;), those strategies are mostly for PvP games.

Thank you for the insight into the AI. Things are getting much clearer know. And it seems that we have to improve a LOT and will try to produce less cannon fodder ;-).

However, i still have one open question: Does the AI know my units after they are encountered/seen on the battlefield (what is realistic) or does the AI know my units after they have been produced?

You need to produce different units not all the time only one type of unit. If i understood you correctly you are making tons of conscripts. Try to learn what units are good vs other units, try to think like AI.

Also you can try to sneak to enemy base with sniper or better sov arty spotter and see what your enemy is doing so you can prepare yourself ;). Try to make forward base.
Maybe some expert players will know better how to defeat Hard/Expert AI.

Answer to your Question:
IIRC AI "cycle of thinking" is 4 seconds so you can say AI updates his "knowledge" every 4 seconds and then it knows what units you currently have. Seen on battlefield would be realistic but AI would be then kinda stupid and all calculations would have to be changed.
For me it is realistic now for example AI knows that you have sniper but he does not know his position on the map so he is hunting sniper with motorcycle that does not mean that AI will kill your sniper with motorcyle. AI can lose motorcyle, AI can kill sniper with his sniper, AI can kill sniper with any other unit, etc. AI only knows that there is sniper on map and AI will try to find and kill sniper with motorcycle, sometimes you can see when you retreat sniper motorcyle will try to catch him and kill him.

Last edited April 24, 2012 at 12:53 PM by jojorabbit

Pfingstei wrote:
Are probability values affected as well? It feels like our units hit less frequently whereas the AI units are more likely to hit our units....From my point of view, losses should feel like "the opponent tactics was superior to my one"...additionally feel like "the opponent seems to know everything", "my units are failures" or "I somehow feel betrayed".

It certainly seems like AI vehicles have higher combat effiency than player vehicles.

I agree and wish the Aesthetic of play (not necessarily realism), would receive more emphasis.

The Computer Sees All and Knows All, (SAKA). The AI Sees All but only Knows what it is programmed to know. Sometimes the Coder will deliberately prohibit an AI tactic if it is viewed as an "Exploit" vs players.

The AI can only know about your OB after units go into production.

JoJo: Good explanations. Are you certain about the 4 second Strategic response time.? Your flow diagram would suggest the Strategic response time could be 8 ticks.  Might be handy to have a variable Strategic Response time to balance Normal/Hard/Expert. PM me about this.

IMHO the Key to victory in CoH is anticipating what your opponent is going to do next; whether you are a Player or Compstomper. This is what JoJo was talking about when he started the "Soviet Strategies are too predictable" topic in Balancing. In this regard the Sovs should have a fast rcce vehicle (not a BA64 type combat unit).

Well, this discussion opened my eyes :-). I guess the fact that the AI always produces anti-units against my units may explain why we feel to be disadvantaged when units meet. They meet units which have been produced to kill them. Nonetheless, we will keep both eyes on the interaction of units. We often see small bazooka units (hopefully specialized for tackling tanks) eliminating our units actually equipped for eliminating infantry.

The key message may be: It is not possible to run away as the AI knows everything (besides the position of the unit). Hence, the only solution is to support units by other units which is possible on open maps or at narrow points, e.g. bridges. We already were successfull in that situations. However, in my point of view, effective defense is hard to be realized on maps crowded with buildings or a pattern of forest parts.

Quote It is not possible to run away as the AI knows everything (besides the position of the unit).

It is possible you just need to support your units and if you think you will lose make some backup units. You can't counter puma with tons of conscripts, sometimes if you attack puma with bazooka like weapon you will see how puma goes away from you trying to find units that can't kill her ;).
Also try diff combo units, like hmg/bunker to pin them down then blow up with mortar or something similar then AI will have to reinforce a lot, Protect you ATs, etc. Experts will know better then me.

In some situations like bazooka situation AI looks if you have tank spawner building(Tank hall, tank depot, etc) so he prepares bazookas to counter early vehicles/tanks.
What i have noticed when you see pak on the map Axis AI is close to pumas and stugs so prepare for them ;). Build mines, upgrade sticky etc.

As i told before ppl don't want unbeatable super trooper AIs in strategy games, but a lot of practice is needed to beat high lvl AI with res bonus. IMO when facing res bonus AI you need a rly smart and good tactic to counter and outsmart AI calculations. Also AI makes mistakes in buying units that is what makes it beatable, Expert ai makes rly low mistakes in calculations.
For Normal and Hard mistakes are around 20%-25% for Expert i think 5-10% to buy wrong unit am not 100% sure abut this need to check out.

Easiest are maps with bridges then blow up bridges so AI has only one path to come to you, example Vire River Valley.
Open maps are kinda hard.

Easy AI does not calculate that makes -> AI does not know anything about your units and how to counter them, he just produces units randomly also never goes fast vehicles.

Other AI calculates and that is why you need support, etc.

Great infromation guys, I knew the AI was complicated but I never knew it had all knowledge of my production.

MBJrP36 wrote:
Great infromation guys, I knew the AI was complicated but I never knew it had all knowledge of my production.

Well in most cases AI counts only units that are already produced(units on the battlefield), on some other cases AI counts also units that you are currently producing(units that are in production). Example you are producing tank AI will count it and prepare AT to counter it or bazooka, etc.

No problem, if you have any other questions about AI feel free to ask i will try to answer them ;).

And I always wondered why "normal" of Eastern-Front feels like "hard" of standard COH. Now I'm a bit afraid of the upcoming matches against the AI :-).

Thank you for the hints.

QuoteIch bin Compstomper - Otto Kennedy

If you want to beat the AI... misdirect it. Build barbed wire and tank traps to block its optimum pathing routes. AI will have to recalculate (Like a GPS). Delay production of units so you can start to produce two or more different threats at once. AI will have to recalculate. Work on both flanks simultaneously. The AI will have to recalculate. Each time you force the AI to recalculate it will require a 4 sec delay to the AI's response time. This also works with players but in a different way. Compel the Enemy do not be compelled. There are many aspects to the Gentle art of Defencing, But when you go on the Offensive BE DECISIVE. If you have good recon you will see the Point of Decision. That is the time to strike!

Quote"On to Ostheer" - Feldwebel Otto

as a note, congrats to jojo on becoming a dev!

QuoteAnd I always wondered why "normal" of Eastern-Front feels like "hard" of standard COH. Now I'm a bit afraid of the upcoming matches against the AI :-).

Don't be afraid be very afraid ;) LOL -> this is not supposed to be rude just a joke :)

Quoteas a note, congrats to jojo on becoming a dev!

Thanks.

QuoteDon't be afraid be very afraid ;) LOL -> this is not supposed to be rude just a joke :)

Don't worry, at least I have an idea now what I will meet soon on the battlefield. If I produce an anti-tank crew, the AI is likely to order e.g. a sniper or a mortar crew :-).

Do you know whether the standard COH AI is based on a similar concept?

QuoteDo you know whether the standard COH AI is based on a similar concept?

Yes all strategy based games are made with similar AI concept, AFAIK there is no other way to calculate.
In connect4 ai calculates his and your moves on those results he takes best move if step is high(more moves to evaluate) then you have unbeatable ai and only way you can "win" is to make draw game ;).

Well here is more about how ai works:
AI takes all units that he can build, puts them in table and gives them unique number (demand), that number represents some sort of "unit value" (something like how much is unit good vs enemy units).
Lets say AI table is this:
-------------------------------
1. puma
2. granadier
3. hmg
4. sniper
5. volks
6. pio
----------------------------
AI wants to counter infantry with this table all units in table are good vs infantry some of them are much better vs infantry some less better.
Expert AI will pick one of the first 2 units in table(puma or granadier) so he has rly low chance that he will not kill you. While Normal AI picks units randomly from table.
For example he can pick pio vs your rifleman, and kinda make a little mistake that is why normal is not too hard to beat he makes a lot of mistakes.

Hope it helps ;).

Some good games have two difficulty settings:

AI Difficulty, AI Handicap

Which can be adjusted separately. So players can play more variety of games against AI: Smart enemies with little resources, or dummies with lots of resources (like real soviet strategies were  :D )

Greetings,

I play 'comp stomping' solely because I have no time to dedicate to a game against humans as I to often have to pause my game and walk away..not good in PVP. Also, I completely suck at mouse/keyboard management due to arthritis of the elbow and hand/fingers (and brain but that's a different story!). But to give you my 'street creds' I will say that I have so many hours stomping the comp in COH/EF that I could have worked a second job last year. Dunno if that's good or bad (but I WILL slay you if you tell my wife!!!)....but if I play against more than 1 comp AI opponent, one is always Expert level and the other is Hard level. As I speak I have a game of COH open on my comp against an Expert Brit and a Hard American. I am Wehr and my comp AI partner is PE. I am currently losing......but that may change! Read on!

So here are my tips on beating the AI:

1. Forward base: You will almost always lose if you cannot reinforce your units without sending them all the way back to home base. Create a forward base ASAP, even if it is just a halftrack. This is hardest on the Brits as you typically have to wait until you create a second truck. When doing this forward base, make sure you grab it with enough units to hold it as the AI will often decide your forward reinforcement point is the main threat and throw the kitchen sink at it. I call this the 'first fight' and it is imperative that you win it. Grab your spot, create the reinforcement point, and hold it! See # 2 for best placement of your reinforcement point....

2. Find the AI's 'key point': The AI will always decide that one or more points are 'key' and if it loses that point it will throw everything at it to get it back. I use this to overcome my AI partner's crappy play (esp Brit on AI...the AI completely sucks for Brits and I feel having them as a partner is especially bad..so I use them all the time as partner) by grabbing a key point, establishing a forward base near it, and hammering the opposing units as they try to retake the point. This often negates the resource bonus of hard or expert level as the AI throws units into the teeth of your defenses. I routinely inflict casualties at 4:1 or better ratio around the key point. This may cause you to not be able to advance, but it frees up your AI partner to stomp the opponents and suddenly the game is yours...

3. Stay Aggressive: Don't allow the AI to hold onto res points too long. Take them even if they aren't contiguous to your areas and you gain no resources from it. Make the AI react to YOU, don't react to it or you are toast. The AI will always send all its units to the front lines, so find their 'stream' and go around it to cut off the bulk of the resources. This also gets the AI into a 'too many units' scenario which will work well for you.

4. Stay in the Game: Never give up. Eventually, the AI will 'run out of steam' and either stop producing units at all or only produce the unit is thinks is its best unit. This can result in a ton of Hetzers...but not enough forces that can cap the ground they force you off of. Stay in the game, it is never 'unwinnable'! Remember your opponent is AI, not a human. It may well pound you into dust...it may well do something silly that lets you back in the game.

5. Watch for bad randoms: There are games where it seems the comp can't miss and you can't hit. I've seen a Marder put 6 (six!!) rounds into an M18, all hits and 3 'bounced off', 3 scored minimal damage, I lost the Marder to the M18, and the M18 drove away....I've put 3 grenades into a building with a grenadier squad in it and killed no-one, and the AI cleared 2 of my squads from buildings in 2 'atomic' grenades..sometimes the 'random number generator' is completely in your opponents favor. When this happens I find the best defense is to defend hard and update your troops to get the bonuses. It seems the only way to offset the AI's better 'random numbers'.

I hope these tips help you out. I do lose games, but that's what keeps me playing COH. If I won every game it would be boring and I would move on :)

S! (Salute!)

Chumley

Hey Chumley! I am glad to see another Stomper with a Cause. I too have issues that prevent me from enjoyably playing real time PVP. If it wasn't for real bad health, I wouldn't have no health at all. Send me a PM if you want we can talk.

Your comments on beating the AI are interesting. Do you play 500 Victory point games? I do. I find that creating more interesting play scenarios more satisfying then simply beating the AI. In this regard you may consider locating the maps that are unbalanced for one side or the other based upon starting positions. Some maps, like Grodno or Silver's maps are balanced in this regard. Other maps like Kursk are not. (I am speaking for AI play here). Kursk is much more difficult if you reverse the "fixed Start" locations. In this case on Kursk it applies to both Wehr or Sovs. Karkov is another example.

I have to disagree with your observation regarding the "AI key points". It is true the AI will fight for Victory Point locations. It is less obvious that a geographic or resource point is preselected by the AI. Evidence for this is: If you wall off a resource point the AI ignores it. If you wall off a combination of victory point and resource the AI will assault the "walls" to obtain access. Frankly in EF_mod this is an exploit when playing against a Soviet AI. Simple barbed wire will deny the Soviet AI access to large areas until they obtain vehicles that can crush wire. I hope that ultimately the Devs will remove this exploit.

Regarding Aggressiveness: Keep the AI moving. Securing resource and victory points at disparate points will cause the AI to react. When they send a stream to the threatened points hit a target point in a different area. The AI reacts quicker than we do but does not seem to change targets in mid stream.

Regarding bad randoms: I know just what you mean. It almost seems like the AI squads have different Stats than player squads. The AI prefers to attack with a 1.6:1 superiority. You should go for a 2:1 superiority in order to overcome this characteristic.

I would be interested in your views on maintaining situational awareness given the difficulty we both have in micro. The comp sees all, knows all. It is difficult to manage multiple task forces and  too easy to lose track of individual ssquads sent on a specific mission. Any ideas?

Chumley wrote:
This is hardest on the Brits as you typically have to wait until you create a second truck.

This made me wonder...

My general build order as the Brits is Tommys, Bren, Tommys, then pack up base and speed governors (only on high resources). That way, your recon can cap the most important locations, while your "slow" infantry can capture at least one flag before the bren carrier is out. Stick them in the carrier, run them to the most tactically or resourcefully independent spot, capture it, and by that time, your HQ is on the move to lock it down.

You may be light on your feet at the beginning (with only a recon and another, bren-less squad to do the rest of the capturing), but that means you can lock down important areas and defend them within two minutes or so.

Is the AI programmed to attempt things like this with the Brits? I have seen them rushing HQ's about, but do they focus on important locations above all, and are they ever this fast to mobilise?

They like to stick their HQ on the front lines which result in their imminent death ::)

The CW AI is programmed for a quick start and indeed when it has deployed three cappers it can really develop quite quickly. Optimally the AI will cap at least 5 resource points before it mobilises its second HQ Truck. It also starts a sim city development at the second HQ's location. What the AI code does not address is how to optimize the location for the second HQ relative to resource collection and enemy threat activities. For this reason much of the AI code for CW HQs has been disabled. Jojo figured out how to undo the disabled stuff but until someone comes up with a good optimization algorithmthe Suicide Highlanders HQs will be a problem.

AFAIK the AI will not move an HQ (even when the code is "enabled"), unless there is another HQ locked down.

@Bacon: If you can get the performance you are speaking of in two minutes, that is really excellent. When the AI code is sound and clever it can outperform human time projections significantly, I have seen 4 light tanks on the field in under 10 minutes for the Sovs on normal AI. The maximum time allowed to develop clever programming is 7 minutes for the Build Order Phase. Unfortunately during the BO phase there is no reactivity to enemy developments (unless a ~2 minute period of chaos is introduced). Hope some of this is helpful.

Cheers Otto! You have quite an insight into all of this! And by the way, I'm all for changing the support truck HQ name to "Suicide Highlanders HQ".

On another note though, I was thinking about the AI markers that we use on the maps. You can place three types, seemingly prioritising the importance of the location. Does anybody have any ideas as to what degree these work? I have noticed that they are drawn to these markers, regardless, but what does the difference between "low", "medium" and "high" entail?

Bacon, your question(s) are somewhat confusing. I think perhaps you are asking two different things here?

The ping markers do work. I have seen numbers associated with the ping markers but have no idea what they mean or how they work. The capture, attack and defend pings do work when playing with AI. Capture and defend work differently then capture. Allied blobs will move on a line/front towards attack/defend markers. They are subject to traffic jams/gridlock. when manuevering "your" ai blobs, I frequently find placing the attack/defend pings perpendicular to the blob's linear orientation works very well. Use baby steps not large changes in objective distance. If you are playing 3v3 you can cause the allied formations to flank the enemy blob on either side. This will allow you the player to seal the pocket. VERY SATISFYING.  On a 2v2 scenario you can manipulate your ally to attack on a approach that protects the player flank and should be oriented towards a converging objective point towards which you as the player are concentrating. In this case I usually park the Zis Good Humor truck in my "ally's" base area to support his activities. Hopefully Jojo's fix for AI ambulance lock-down bug will be included in the next patch of the game.

Capture ping used for AI allies is tricky. Try to time the use of this button for right before your ally finishes capping a nearby point.

When you referred to the high, medium and low markers I presume you were talking about resource points. The AI works with these a little differently. VPs are to be considered here as well; although the AI code for VPs is separate from resource points. The AI sets priorities for resource acquisition on at least three levels. Basic game orientation, (unchangeable once the code is written), Difficulty level priorities, (which have two sets of instructions per difficulty level) and Personality/Build Order priorities, (which can be set for different Build Orders and Personalities in each different game). The AI can be set to prioritize Fuel or Munitions. The AI can be programmed to prioritize securing high/low or medium resource points. Part of the Suicide Highlander problem is usually the priority is set to secure high resource points; which will place the HQ in a dangerous sector and cause the truck to move through dangerous sectors to get there.

There are several ways the AI prioritizes VPs. The main thing to consider here is if the AI VP control drops below a certain percentage, (Say 50 %), the AI will change its resource acquisition priorities to obtain VPs to maintain the preset VP priority, ON A TEMPORARY BASIS. Clearly there are opportunities here for the player to disrupt the AI programming goals. The AI also prioritizes fuel and munition point acquistion over SPs. Not only are there opportunities to disrupt the AI programming here but You should incorporate this into your strategy when planning your capping strategy if you have an AI ally. SPs cap quicker < low < medium < VP (I think) < high. Cut-offs are particularly significant when playing against AI at higher difficulty levels.

I hear wonderful things of your mapping skills. Keep up the good work!

Last edited November 20, 2012 at 2:12 PM by Otto Halfhand

Thanks for the reply Otto, but we've gotten onto different points here! I'm referring to the AI control points that you can't see in game. They are in the gameplay resources on Worldbuilder, and are added on the vast majority of Relic maps. They seem to direct the AI towards specific locations, but I was wondering if anybody has real information on them.

They are signified by large, 3d arrows in red, green and blue, but as I said, they are invisible in game.