To offer a brief explanation of ground combat mechanics:
Firstly the action order is worked out:
1) All armies take their actions and initatives. All initatives are jittered by a uniform random function 0-4, so you need 5 or more initative differential to have 100% guarnteed precidence.
2) Actions are stacked in reverse order of initative. The army with the lowest initative puts down an action, followed by the next lowest until all have put down one, then the process repeat. Any spare actions are then stacked on top.
For example if we have three armies with initative/actions of A - 3/3, B - 2/5, and C 6/6, the action stack will look like so:
[Start/Stack Top] C CB CB CAB CAB CAB [End/Stack Bottom]
3) We then proceed through the actions until the end or an army is all dead/captured. Actions not used are wasted.
4) Actions are:
-MOVE: Move from one region to another, if the transistion is over water or impassable terrain it needs an navy/airforce. being dropped from orbit into an undefended region counts as the first move of an army.
-DIRECT ATTACK: An army attempts to move into a region controlled by another, and makes an ground combat roll in the calculator. If the defender is brought to 100% Wounds the attacking army moves into the region, otherwise it does not. If the attacker is brought to 100% wounds it is captured. If the 100% wounded defender has actions left it can flee the region, if it is still in the region at the end of the ground combat round it is captured.
-DISTANT ATTACK: An army skirmishes with an defender without attempting to move into the defenders region. it attacks with less strength, but is not captured when brought to 100% wounds.
-DISTANT ASSISTANCE: An army lends its distant attack power or defence power to a friendly army making a direct attack or direct defence. It takes no wounds.
-DISTANT DEFENCE: An army interdicts the movement of enemies into a region adjacent to itself, and defends against attacks with its distant defence power. Once brought to 100% wounds it can no longer distant defend, and unlike defending a region directly, distant defence consumes actions.
Armies cannot make attacks or lend assistance once they have now active personel left.
Distance assistence and defence can be assigned at the start of a year if the army remains immobile. In the example above if A decided to make no moves and instead distance defend two ajacent regions (one twice), the action order would become
A (dd R1) A (dd R2) A (dd R2) CCBCBCBCBCB
The first of C or B to move into R1 or R2 would face a distant defence action from A, but only if A chooses to make no moves this turn.
-STEALTH MOVE: An army can attempt to move by stealth, if successful the enemy army can't intercept and attack it. Once stealthed in the same region as another army it can launch a surprise attack (where the foe has 0 int and defence equal to their distant defence score) or do a stealth mission. Stealth moving into a region, doing a stealth special mission, and stealth moving out of a region counts as 3 actions.
-SPECIAL MISSION: Special missions mean stuff like destroying infrastructure, raiding stores, raiding data, terrorism, assassination, extractions of specialists and PoW, a complete list will be forthcoming later. Some can be performed at distance, but distant stealth is more difficult. If you control the region they can be done automatically (but at the cost of actions).
-SEARCH: An army can search the region its in or adjacent too for a stealthed army, which must make a successful stealth roll again. The stealthed army succeeding at this does consume one of its actions.
-ELECTRONIC WARFARE: A army can make an EW attack against another army in an adjacent region using one of its actions. This can be performed as a stealth action, and if successful the effected army will be unaware of the action.
5) At the end of turn any captured armies are converted into prisoners (PoW) and Talented prisoners (TPoW), and all their equipment is lost (its just easier to manage this way), each Pow and Tpow consumes 0.5 f and 0.5 e a year. Once returned home Pows and Tpows can be recouped back into civilian populations or added back into armies as manpower or in talent costs. If ordered to your armies can take no prisoners, but it may make people dislike you.
6) Healing also occurs at the end of the year, and wounded manpwoer converts back to active.
Most of the time your orders to the armies will be just short objectives and battle conduct guidelines, but I might make you game the occasional battle out.