As noted in many places over the last years, it could be a nice idea to implement some kind of ambush mechanic. So this is my attempt.
This patch gives the Gauls an "camouflaged ambush camp", which can be build in neutral territory while ignoring obstructions and is not directly/ automatically targeted by the enemy (by that I mean BuildingAI and UnitAI).
The human player can still see and attack it, so it's not invisible and it should better be hidden in a forest (ignoring obstructions for that reason).
To make it harder for the enemy to find the camp by scanning the forest by hand, the camp has a small bounding box and is not visible in the fog. So the enemy would need to be in the LOS to do that.
Credits go to @wowgetoffyourcellphone from whom I got the "grove" idea, after which the camp is
and @bb who gave some helpful tips
Sidenote: My first thought was to do this concept with the tree grove (as in DE), but since there are no groves in EA, this is the closest I could get.
Here is a short video demonstrating the core mechanic:
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