Quote Originally Posted by SirNibbles View Post
As long as the martial doesn't have some way to fly, Caltrops will stop a charge. Also, breaking line of sight by using smoke or something similar will prevent charging.
That won't, however, stop the same character from running. Especially on flat, open terrain. Just angle to the side around or beside the caltrops/smoke so you don't have to run through difficult terrain or where you can't see. Wearing medium armor, a human can run 120 feet in one round (so mithral plate). You forfeit your dex bonus to AC (but this likely isn't much anyway), but you've crossed the entire field in a single full-round action.

Just wanted to say that is all. 100 feet is a pretty tight playing field when you consider that.