From: Utlima Thule
First, all the details for this can be found in the invaluable combat thread on the AGE Wiki.
When learning the AGE game system I found the issue of stack selection in combat perhaps the least obvious. It is also important as unlike the details of the actual combat engine (to come in later posts), its something you as a player can control through army organisation and use of stances.
I'll start with the rules, and then a short discussion
1 - Stacks are sorted into three groups depending on stance. The groups are assault/attack (remember that for open battle these are the same); defend; or, passive (the green option)
2 - one stack (at random) is selected that is in the assault/attack mode
3- it then tries to chose an enemy stack that is in assault/attack mode and that is not already under significant attack. This will prioritise a stack that is not moving (ie was in the province at the start of combat) over one that was moving (ie has arrived via the MTSG mechanism)
4 - if there are no enemy stacks in attack mode, it will pick (at random) one that is in defend mode
5 - if no there are no enemy stacks in either attack or defend mode, it will pick one that is in a passive stance
6 - the game engine then picks another random stack in attack mode. If this is the one already under attack, nothing else happens and the game engine picks a new stack and that stack selects a target as in 3-5 above.
7 - once all attacking stacks are engaged, the stacks in a defend mode will either join an existing battle or pick an opponent as above
8 - very important... If there is a HQ stack present as well as other stacks, the HQ will not attack in its own right but will support an existing battle
The inverse of rule 2 is that 2 armies both in defend mode won't start a battle - this is unlikely but can happen if both sides share military control (mc) in the province. Usually having low mc will force one side into an attack stance.
Rule 3 makes it possible that a stack arriving via mtsg will take the enemy by surprise, they are fully occupied with the in-province units and all of sudden you can gang up on one enemy corps
Rule 5 means that if you have a stack you need to protect, if it is in the green stance it has a good chance to evade combat
Rule 7 means it is possible for a stack in defend mode to opt to join an existing fight
Rule 8 has significant implications. If you have just a single army stack on the battlefield, it behaves like a normal unit. If the HQ stack is with other stacks, it will only fight in support. This allows you to do one of two things. First your HQ can just be the CinC (even if they join a battle they will be fairly safe as there should be lots of troops between them and the enemy). Or you can put your elite reserve in with the HQ stack. Then it will fight in conjunction with a regular force and you have an excellent chance of overwhelming the enemy.
edit - a third option is to put all your badly battered units in the HQ stack. This won't completely protect them but it does mean they will only fight in conjunction with fresh troops. This used to be a common gameplay approach in Rise of Prussia.
All this I think has some implications for how you organise your army and there are advantages and disadvantages to different options.
First, its quite by design that a large corps may target a small one. Bad news for the small one.
Second its by design that multiple stacks can gang up one (once the first round of target selection is over). Note that corps arriving via mtsg have a lower chance to be selected as a target than one already on the battlefield. This might allow them to double up on a target.
Third, if you have lots of small corps, you are taking a chance that they will be overwhelmed, but a few large ones may hand the initiative (ie the ability to gang up) to the enemy. Purely from my own point of view, I tend not to use small corps, I think its too risky, if I am likely to engage in a huge battle.
I've also lost battles where only one formation was targetted but been able to turn the tables next turn. Odds on all the enemies stacks have lost cohesion etc, only yours that actively fought will be in that state and the others fresh. I still have a warm feeling about an Italian victory at Adrianople over the Ottomans (in Pride of Nations) that came due to this ability to turn the tide after a defeat.
< Message edited by loki100 -- 12/6/2015 12:07:26 PM >