Combat in Bad Going - All or Specific?

Quick answer - the second one

If you look at the Combat Outcome section on page 11 it tends to specify when bad going impacts on the outcome. So for example Kn kill Ax if they beat them and if the Ax are in good going, but if the Ax are even partly in bad going then there is no auto kill for the Kn unless they double the Ax.

If the Kn were in the bad going and the Ax were in good going the Kn would get a -2 in combat but would still destroy the Ax if they beat them and didn't double them.

However Bw are destroyed by mounted if they are beaten and not doubled whatever going they are in.

Also Ps are not destroyed by Cm when beaten if the Ps are in, say, a marsh or wood etc because Cm count that as bad going but they would be destroyed in Dunes because Cm count that as good going.

In HOTT I think mounted suffer a -2 if they are fighting troops in bad going, even if they are in the open themselves, this doesn't apply in DBA 3.0

Hope that helps