Area of Effect
The Area of Effect is a red box zone that surrounds an enemy Camp, but not a Leader's Camp, that denotes the area that, if strayed into by an attacking General, your General will be drawn into a battle.
You know when you've been intercepted as it pops up in a warning message at the top left of your screen, just like an Email notification does.. and indeed sends you an email too, giving you some time to find the Garrison and click Retreat.
Advanced Use of Areas
Several of the Adventure maps use this to their advange by laying traps where a camp (Forests of Wolves for example) are disguised amoung trees and create an ambush. The hidden Camp can be clicked on if you mouse over it.
Attack path
Other tactics are to have one or more areas overlap. In these cases you have to watch your general's attack and see he doesn't get intercepted to the other camp. This also leads into the user tactic of Blocking to distract one camp while you attack another within it's area of effect.
In some cases attacking the wrong camp to get intercepted is desireable to avoid an even worse battle. In this case your general will get intercepted, clear the camp and then will head for the original target (which you presumably wish to regoup for) and so you will want to Retreat from it.
Note
Areas of effect do NOT trigger if:
- The General is Transferring rather than attacking
- The General is returning from a lost battle.