Quote Originally Posted by Omanes Alexandrapolites
I must admit that trapping is a very useful tactic. In many cases I have lured enemy units onto superior force through this tactic. As the word hidden suggests though, it's best used when combined with tree cover and, in the case of units with excellent ambush abilities, long grass.
When a cavalry unit is chasing your "fleeing" unit, they don't seem to see much but your horses cute rears... well they sure seem to run into spearmen awful often, and then get clobbered by heavy cavalry without any cover at all. Perhaps the non-spear infantry units "screen" the trapping spearmen. I haven't needed the trap to be "hidden" at all, open ground fine at least with 'impetuous' units. Worked for me a treat against Barb cavalry and Macedonians, for instance.

The main problem is when the battle seems to run at double speed, and large number of forces, are close together so you don't get time to spring trap, focus elsewhere and rest your gallopers before next round.