Terrain effects on combat

[Yitzi]

So I've read the rules about when which difficult terrain bonuses are applied (assuming non-psi non-artillery), and here they are:
-If the defender is an air unit, or is in a sea square, there are no terrain effects.
-If the attacker owns the Pholus Mutagen and the defender's square has fungus, there are no terrain effects, even if the square is also rocky.
-Otherwise, if the square is rocky, it has the "rocky" effect for +50%.
-If it is not rocky, but has fungus, it has the "fungus" effect for +50%, or +100% if the defender is a native life unit (with modding, native life can lack psi defense, though it always has psi attack*) or owns the Pholus Mutagen.
-If it is neither rocky nor has fungus, but has a forest, it gets the "forest" effect for +50%.

Anything with any of these effects, or a base, is considered rough terrain, losing the "mobile in open" bonus and getting the "defend vs. mobile in rough terrain" bonus (if any).

*The way the program determines if a unit is native life is that if it's both predesigned and has a psi attack, it's native life.

[Yitzi]

By the way, the fact that rocky+fungus squares use whichever effect is weaker (i.e. rocky blocks fungus if the defender is native, fungus blocks rocky if the attacker is native) seems strange, and if the consensus is that it's a bug then it can certainly be nominated for fixing.

[Lord Avalon]

It seems to me that a sufficient number of large rocks might prevent native life from moving about smoothly despite the presence of fungus, but should still provide cover to humans.

[Nexii]

A little confused here.  Why would you have native life with standard defense?  This seems really unusual to mod this way.  But either way I haven't tested this.  I would say that the fix would be for the defender to just get one modifier, the largest of fungus or rocky (they can differ if modded) in these situations since a tile can have both.

Though as an aside I feel like native psi defenders should get a defensive bonus in fungus when attacked by non-psi.  They get a bonus attacking into fungus for the same situation.  Also native life does get their movement speed increase over rocky+fungus

[Yitzi]

A little confused here.  Why would you have native life with standard defense?  This seems really unusual to mod this way.

Unusual or not, that would be the effect, just as it is the effect with Pholus Mutagen and standard defense.

But either way I haven't tested this.  I would say that the fix would be for the defender to just get one modifier, the largest of fungus or rocky (they can differ if modded) in these situations since a tile can have both.

Though as an aside I feel like native psi defenders should get a defensive bonus in fungus when attacked by non-psi.  They get a bonus attacking into fungus for the same situation.

Any of these things can be nominated for addition as a feature, or the former as a bugfix if the consensus is that it's actually a bug to use the lesser of the two.

[Nexii]

Actually for some reason I thought defend in rocky, fungus, forest, etc were variables in alphax.txt, but they aren't
I'm guessing then that the code here is kind of incomplete, my vote is for bug - the higher of rocky/fungus should get applied.  if not adding these as variables I'd say just bump the Fungus order of precedence to before Rocky and Forest

[Yitzi]

Actually for some reason I thought defend in rocky, fungus, forest, etc were variables in alphax.txt, but they aren't
I'm guessing then that the code here is kind of incomplete, my vote is for bug - the higher of rocky/fungus should get applied.  if not adding these as variables I'd say just bump the Fungus order of precedence to before Rocky and Forest

It's already before Forest; would you want to put it before Rocky even when the attacker has the Pholus Mutagen (so putting it before Rocky means no bonus)?