Terrains still affect the likelihood of RFC (retreat from combat) or not?

[selfoe]

In TOAW III 3.4 the manual explicitly says that the RFC probability will be reduced by 83% if the unit is in a fortification line.

However, I find no information in the TOAW IV manual. I wonder if this mechanics still exist.

[golden delicious]

It's pretty well buried but I found in the header for section 13 of the manual:

...terrain affects RFC odds...

This is because defender strength is modified by the terrain (and deployment of the units in question), and defender strength is one of the major factors in the RFC calculation.

[Lobster]

In TOAW III 3.4 the manual explicitly says that the RFC probability will be reduced by 83% if the unit is in a fortification line.

However, I find no information in the TOAW IV manual. I wonder if this mechanics still exist.

13. All Battles Are Resolved
...
Retreat From Combat Determination
§ At the end of each combat round, units
that have not dropped out of the attack or
retreated from the defense will be used to
determine the current Assault Strength Ratio.
This ratio is then further modified by terrain
and deployment scalars of the defender’s
position appropriate to the equipment types
in that defense.
...
§ Remember that the ratio takes into
consideration to what extent the defenders are
armored or not and the assaulter’s AP vs. AT
strengths. The net effect is that terrain effects
and combat odds scale the Quality check.
This means that terrain affects RFC odds yet
even fortified locations can be overcome via
employment of heavy combat odds.

[selfoe]

Many thanks! I thought in Toaw IV, terrain only affects the RFC indirectly through AT-AP bonuses.

So now is the effect of terrain double counted?

For example, first the terrain will increase the defender's AP, improving the strength ration.

Next, the "ratio will be further modified by terrain".

In TOAW III 3.4 the manual explicitly says that the RFC probability will be reduced by 83% if the unit is in a fortification line.

However, I find no information in the TOAW IV manual. I wonder if this mechanics still exist.

13. All Battles Are Resolved
...
Retreat From Combat Determination
§ At the end of each combat round, units
that have not dropped out of the attack or
retreated from the defense will be used to
determine the current Assault Strength Ratio.
This ratio is then further modified by terrain
and deployment scalars of the defender’s
position appropriate to the equipment types
in that defense.
...
§ Remember that the ratio takes into
consideration to what extent the defenders are
armored or not and the assaulter’s AP vs. AT
strengths. The net effect is that terrain effects
and combat odds scale the Quality check.
This means that terrain affects RFC odds yet
even fortified locations can be overcome via
employment of heavy combat odds.

[golden delicious]

Many thanks! I thought in Toaw IV, terrain only affects the RFC indirectly through AT-AP bonuses.

So now is the effect of terrain double counted?

For example, first the terrain will increase the defender's AP, improving the strength ration.

Next, the "ratio will be further modified by terrain".

As I understand it, the assault ratio is based on the ratio of the AP strength of the attacker versus the active defender strength of the defender. It's on that latter figure where the terrain comes into play, as terrain (combined with deployment status) can add (IIRC) up to a x4 multiplier to the defence strength.