We’ve already run through the basics of the mission system. So you are probably wondering what else is new in Hearts of Iron 3.
There are two major changes. The first one is doctrine effect on air combat. By focussing on doctrines you can influence how your air units behave in combat. There are two sets here, one for air-to-air combat and one for ground attack. For air-to-air you can research fighter and bomber focus. This determines its targeting priority for mixed stacks of enemy units. The names are pretty self-explanatory, on the one hand you can take more damage in the short term and attrition down enemy fighters in the quest for air superiority, on the other hand you can aim for the enemy bombers and reduce your own damage from enemy bombing.
The second is front line and reserve focus. Here this influences which types of enemy units air power will bomb in when doing ground attack missions for enemy stacks in combat. You can aim for the front line units to try and force a break through or concentrate more on reserve units in a quest for generalised attrition against the enemy.
As I mentioned these come in pairs so they are not mutually exclusive doctrines. Essentially these techs supply a weighting value; identical levels of research give equal weight to the targeting choices.
As a side note you are wondering about the power of air bombing on ground units. Well this is the subject of much testing and balancing, but from our own internal tests air power comes into its own when units are fighting in combat. There the combination of bombing and fighting can induce units to shatter much quicker than they otherwise would. Regardless of which approach you take, bombing the reserves or the front line, close air support can swing battles.
The other big change is unsurprisingly AI control. Air units have no individual command structure; instead a stack of air units is always classed as a brigade. Thus any HQ in the chain of command can have air support attached to them. When on manual control this doesn’t actually mean anything as you order around the air units yourself. However when on AI control this can allow you to better control your air assets. Let’s say you have three army groups on a front but all your offensive objectives are in front of only one of those army groups. You can assign air units for the sole use of this army group instead of the whole theatre, focussing air power over the area you wish to attack instead of it being spread over the whole theatre.
Now if we reconsider our example and say you wanted to control the offensive army group yourself, you can assign air power to the army groups you want to hand over to the AI and allow them to use themselves without you having to manage both your offensive and air power over the whole theatre.
Now these examples are for large formations, but air power can even be assigned down to corps level. So if you think that a corps or an Army needs some special help for whatever reason you can detach the air power from the high level command and assign down for the exclusive use of this formation. When the help is no longer required simply detach again and reassign up the chain the command.
What we have aimed for is to maximise both flexibility and ease of management.