AI Artillery Spotting

[Zoetermeer]

I have no optional rules enabled that relate to this (only explicit supply and night fatigue). I am pretty sure it's artillery, just based on the sound effects I hear when these strikes happen (and their volume, as this is Smolensk in early July so I expect the Soviets to have almost no air support).

When you said "did you notice if your units were shown as being spotted", what do I use to see that? Thanks!