RE: “ALWAYS PERCEIVABLE” creature property.
I don’t know if this is 100% correct, and it may have already been documented somewhere … however … for some extra feedback about this property, I noticed that when the “Always Perceivable” property for a creature is ticked, it seems to me that if a player was to TAB between creatures (during combat), then this creature can appear a “target” as such, even if it is not currently perceivable in the area due to terrain. (I know that fits the description, but I had not fully comprehended how this played out with respect to other aspects like the TAB.)
This confused me, and became particularly problematic when I was trying to track an enemy count, and TAB between targets appeared inaccurate. E.g. GetObjectSeen would also return TRUE even if there was terrain in the way.
In my case, the property should have been “off” for a couple of creatures where it had been ticked as “on”, as I did not want a player to TAB to a creature that was not currently an “active” (perceived) target.
EDIT: Such creatures will also cause PC AI turned on to run off to attack them even when not obvious where they are.