AI and Walls

The AI does not seem to build walls around its main base very often. Where can I change this? I would like the AI to use walls in every skirmish.

I found some values that I think the AI uses to prioritize which buildings should be built first. For example: if the AI thinks it needs to build a house, but it also needs to build a wall, the house has a higher priority and will get built first. There is actually a fairly complicated formula that takes into account the materials needed to build the house and the wall, time to construct, … I changed the priority of walls and gates to see if maybe this would result in the AI building walls more often. It did not. I tested my changes by playing on a revealed map with max starting resources and starting in Age 4. So the quantity of resources was and technology level were not factors. In 3 out of 10 games the AI built walls. I set my changes back to default values and 4 out of 10 games the AI build walls or partially built walls.

I also found some values in attributes\tuning_ai\tuning_ai\wall. I can not clone tuning_ai though, so I can not make any changes to it.

Any help would be appreciated. Thanks in advance.