I'm currently developing my first game. I had the idea to do something similar to the old browser games like Ogame, Travian, etc (with some differences though), and I'm kind of unsure about how to calculate the output of two armies fighting. There are for now no multiplayer aspect in the game, but that's something I would like to do in the future, si I'd like to plan with that in mind, if possible.
Each unit has an attack, HP and armor value. The armor is regenerated between each round (in my idea). There are different unit types, with strength/weaknesses against other units.
I had two ideas about how I could calculate the outcome of a fight :
1. Loop through each unit
In this scenario, I would basically loop through two dictionary<Unit, Int>) where each int would be the HP remaining on each single unit. One dictionary per army.
I would assign a random target to each unit, apply the modifiers (either a simple attacker multiplier or a chance to hit a new target depending on a value), and store back the HP values.
Rinse and repeat for either a fixed number of rounds or until one army is out.
I love the idea behind this solution, but I'm afraid it could take too much time to loop through big numbers of units. At some points, armies could reach over 1M units (not more than 10M though I think), and even though my operations inside the loop are quite simple, I'm a bit afraid of performance issues, especially with multiplayer in mind.
2. Have a global value
In this scenario, I would just calculate the total Atk/Armor/HP of each unit type, spread the attack value amongst ennemy army (if I have 100 units attacking 50 units of type 1 and 50 units of type 2, half of the damage would be applied to each ennemy), apply my damage multipliers, and get a global remaining HP for each unit type. Then I would divide by an individual unit HP to display the remaining units number. Rinse and Repeat.
This solution is obviously much faster, as I have at max to loop through 4 to 6 different unit type. The issue would be when dealing with smaller amounts of units, I did some tests and I didn't like the results. Also I'm not too sure about how to implement a bit of RNG in this system.
3. A mix of both ?
I had other ideas such as dividing the army in groups of units (let's say an army is always divided in 100 groups), and then apply method 1 to each group. Then I would have some RNG still, but each group would have its global HP. You could then never lose an amount of units smaller than a group.
I'm not too sure about this one :/
My main concern overall is about the method 1 and the possible performance issues. Do you think it's doable to loop through arrays containing millions of values or is it just stupid performance wise ? Any other idea ?
Thanks in advance !