Fortifications

[tbridges]

How do fortifications affect defensive modifiers when used in non-clear terrain? Is the effect cumulative? For instance, is there any point in digging-in in a forest hex?

The forest hex has a -30% defensive modifier while the fort has a
-20% modifier. So if you dig-in, do you now have a total -50% modifier? Or have you actually made your position worse by reducing the existing -30% of the forest to the -20% of the fort?