Developer Diary | Small Features

AI Force Concentration

So WHY did we want to focus on this?

Well, first of all, the AI has frankly not been very good at handling their armoured divisions. Sure, they produce tanks and assign them to fronts, but they are seldom concentrated enough to actually pose a threat for the defender. Second, the AI always pushed along the entire front with equal effort. There's nothing strictly wrong with that, but most military operations have a strategic goal like capturing a city or a supply hub rather than just taking ground, so making a concentrated offensive effort towards a specific goal seems more realistic and human-like. Third, we want to make the combat gameplay more dynamic and interesting for you as a player. If the enemy concentrates more and better divisions in a certain sector, it requires you to make choices. Should you meet the anticipated offensive head on, will you lure them into a trap, or use the opportunity to attack somewhere else?

The days before Operation Barbarossa. The AIFC divisions are visible in the right picture as the turquoise army, preparing to quickly take a supply hub in Volyn when the war kicks off.

Cool! How does it actually work then?

For the most important fronts, the AI considers whether it wants to concentrate its forces. If it has enough units available to both hold the line and still allocate units for offensive duty, then it will create an AIFC army. This army will receive the "best" divisions along the frontline, taking into account factors like attack and breakthrough stats, how experienced they are, how fast they can move, and so on.

The AI then evaluates possible targets close to the front line, for example supply hubs, ports, large cities and so on, and it finds a path from the front line to the chosen target. This path is determined according to the path-of-least-resistance principle, which essentially means that it tries to avoid river crossings, bad terrain, fortifications and so on, while also following railway lines in an attempt to avoid ending up in a situation where it can't supply the troops.

The paths evaluated by Germany before Barbarossa.

The AIFC armies follow those paths-of-least-resistance and will continuously update their orders to make sure that the front lines match up with the intended path. Of course, since placing too many units too close together might cause some problems with your Amazon deliveries (a.k.a. your supply situation), they will spread out somewhat along the neighboring provinces.

But as they say, "a plan never survives contact with the enemy". This can be true for the AI as well. Because of this, it keeps track of how well an AIFC offensive is going. If the offensive is going well, by all means let's