About AI purchase behavior and unit costs



  • Hi there
    As i have alot of different units, i try to observe AI purchase after setting my unit costs by running a couple of rounds, sometimes even hours to look if AI will actually buy a unit or not at all. There are a couple of things i noticed and things i just dont understand how the AI evaluate the purchase in terms of unit values and specifically movement.
    As most of you know a 2/2 unit is not as valuable then a 1/3 or 3/1 unit.
    I claim the AI doesnt recognize this at all, which is fine i think.

    One thing i noticed: There is a tipping point when the AI decides to go for another typ of air unit if i lower or higher the cost by 1 and ignores the other air unit for the most time which were bought the most time before i changed the cost value. There is a tipping point. There must be a formula which the AI derives for its purchase.
    And somehow this is related to the movement value i have the feeling.
    Also there is the AI log screen where all unit purchase options are listed with cost efficiency values.

    Q1: Does the AI use any cost efficiency maths to decide the best option?

    Almost all units in my game are being purchased by the AI regularely so i am happy for the most part. But when it comes to air units, i have some problems to track down the best costs per unit.

    Q2: How do you set your costs for air units with different combat and movement values and in regard to sea and land units?

    Also it seems there is a exponential thing going about attack and movement. A bomber with 4 attack and 6 movement or a fighter with 2 and 4 seems not of linear value to the AI.

    Q3: Is there anything like that going on there?

    Sorry, but i am totally obsessed about playing against AI which i want to purchase all my units regularely, which makes unit cost evaluation so much of a important thing. Because the AI does decide whether or not a purchase is worth it or not. So i have to know how the AI is doing its math.

    Thanks for any response

    Edit:
    When i talk about tipping point, it doesnt mean that the AI stopps purchasing a specific unit completely in all cases if i change the cost by 1, it just does then favour another air unit more after the change of cost.



  • One clear example how the AI behaves when it comes to purchase.
    Germany can build 2 air units from start:
    For the matter of simplicity, i only state the most important values (attack/defense/movement @ cost)
    Aircraft A = 2/2/4 @ 9
    Aircraft B = 3/3/4 @ 13
    In this setup, the AI is purchasing only Aircraft A (dozens of test rounds)
    If i either increase A to 10 or decrease B by 1, the AI will only purchase Aircraft B.
    The first thing which irritates me is, that the cost difference between those units seems rather high in comparison to land or sea units in my game, but it was needed to get to the tipping point where the AI recognizes that one or the other air unit is best purchase.

    Normally i would only up the cost by 2 PUs if a unit gets +1 att/def more. This works ok because the AI will purchase both more or less, but is never totally ignoring a purchase like with those air units i mentioned above.
    A couple of land and sea units that AI is purchasing both and never ignore it are the following ones:
    Light Tank = 2/2/2 @ 7
    Med Tank = 3/3/2 @ 9
    and
    Destroyer = 2/2/2 @ 12
    Cruiser = 3/3/2 @ 14
    Those the AI is purchasing both more or less.

    Do Air units have different AI purchase code/formula than land/sea units?


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