Slitherine

I thought structures like coastal guns did not need supply?
Note the orange low-supply marker in the screenshot.
This unit was spawned in a low-supply area, maybe that is causing it.

It seems that if a structure shares a supply "pocket" with other units that have less than full supply, then they lose efficiency too.

- BNC

Yes, structures are also affected by supply even if they don’t use supply/command points.
Looks a bit silly on something like fuel depots, but I guess something is always missing after a while, either fuel, spare parts, ammo, or something for the empty belly.
I’ve given the supplyResilient trait to coastal guns, bunker and fortress types, as they typically horde lots of supplies. Hangars, oil pumps, tunnels, and such have currently the noSupply trait.