Can you make it more clear as to what triggers a counterattack? I think it has something to do with AP, but there's no way to see how much AP the enemy has, nor is this mechanic ever explicitly pointed out in-game like unit costs are (and the tooltips reset after each battle, so if it's explained there, people won't notice because they'll turn it off after three battles of seeing the exact same tutorials over and over).
Viewing post in ToF 0.7.1-beta release comments
The game isn’t very well explained, that’s true. I think the first mission should mention how this works, but I’m not sure. Anyway, unit will counterattack once, if it has any AP remaining, and survives the initial attack on it. This means that, for example, infantry can’t counterattack tanks, as it will always die from the attack. Tanks can’t attack (and counterattack) helis at all. Performing a counterattack will drain the remaining AP, so it can only happen once. Hope that helps!