Quote Originally Posted by Martok
Puzz, don't spearmen & pikemen suffer a mild penalty when fighting in woods as well (albeit not as severe a penalty as cavalry)? I seem to recall this penalty is applied due to trees breaking up their ranks somewhat.
The rationale is that the trees break up the formation which they actually do, but I think the rank bonus is completely eliminated in trees regardless of that. There is no additional combat penalty as far as I know.

Quote Originally Posted by Martok
In fact (come to think of it), I've long been under the impression that sword/polearm infantry are pretty much the only units that *don't* suffer some sort of penalty when fighting in & amongst trees. I seem to recall that just about all other unit types -- cavalry, missiles, gunpowder, etc. -- suffer from at least partially reduced effectiveness in woods for one reason or another.
Trees hamper maneuver and disrupt units when moving (-2 morale), so in that sense all units are adversely affected by trees. Cavalry and camels, in addition to the combat penalty, are hampered the most when trying to maneuver in trees because they are physically larger objects and therefore collide with the trees more often.