I am new to the game, just bought it yesterday via steam. I played HOI 2 and so far I noticed there are huge differences between the two. First, I was wondering why I can’t merge units in this version. I used to merge at least 8 units together in HOI 2 and promote officers accordingly. I also don’t fully understand how HQs work in this version. In HOI 2 they just gave a moral boost to surrounding units.
Also, since I downloaded the game I don’t have manual, is there a downloadable version?
In HOI-2, one counter on the map represented a Corps (up to 12 Divisions). In HOI-3, each Division is a seperate counter, with up to four Regiments (up to five after learning the appropriate Doctrine). You cannot merge several Divisions into a single counter.
HQs give several different types of bonus, depending on the HQ.
Leader Traits (like Panzer Leader or Offensive Doctrine) are passed down to subordinate units, halved at each link in the command chain. So if you had OD Leaders at every level of command (Division, Corps, Army, Army Group and Theatre) then when attacking, your Division would receive +10% for an OD Divisional commander, +5% for an OD Corps commander, +2.5% for an OD Army commander, +1.25% for an OD Army Group commander, and +0.625% for an OD Theatre commander... a total of nearly +20%.
In addition to this, each level of command uses the Leader's skill level for a different purpose:
Divisional commanders add +5% per skill level to the unit's combat efficiency (just like in HOI-2).
Corps commanders use their skill level to improve the rotation of their subordinate units in and out of battle, relieving tired units with fresh ones.
Army commanders add their skill level to the ORG of all subordinates.
Army Group commanders reduce the supply consumption of all subordinates by 5% per skill level.
Theatre commanders reduce the stacking penalty of all subordinates by 1% per skill level.
Naturally, the units must be within radio range in order to get the benefits. You can check radio ranges by selecting the unit and pointing your mouse at the radio icon.
EDIT: Manual:
http://forum.paradoxplaza.com/forum/showthread.php?416093-Manual
If you haven't already done so, I strongly urge you to get the Semper Fi expansion and patch it up to 2.03c; it greatly improves the game.