goken said:
How did people actually defend themselves from arrows in the old days? Sounds like a good question for Gygax, but one can guess. Diving for cover is one. Another is shields and helmets; I allow double protection from such devices against missile weapons. Still... I'd advise ducking for cover just to be on the safe side.
Yes, shields were pretty much the only reliable defense against arrows, because GOOD arrowheads almost always kept pace with GOOD armor, such that any armor (helmet included) which was impenetrable by a bodkin arrow (the very narrow-headed kind) was also too expensive and cumbersome to equip more than a few troops with. Certainly armor that is less than "impenetrable" offers some protection, as arrows rarely strike at the optimum angle to penetrate, but big wooden shields were the only cheap and reliable way to stop an arrow.
Of course, a shield only offers protection for the portion of the body that it covers, meaning that a soldier and his unit must be well-trained in using their shields to provide cover for themselves and each other, or else they must use truly massive shields. Massed groups of spears also deflect and reduce the lethality of arrows if they are raised into the path of incoming arrows and are moved around a bit. The key is training.
Basically, an army's best hopes against arrows were to close with the enemy very quickly to reduce the volleys that can be launched against them, stay out of range completely, or equip their troops with the best armor, shields, and training that money could buy. That left cavalry and heavy infantry (both quite expensive) as the best defenses against archers, unless a tactical advantage could be gained by clever maneuvers and ambushes.
Training archers was expensive, though, and their effectiveness was heavily reduced in inclement weather or extreme terrain, so despite their offensive effectiveness they were not usually used very heavily in the Iron Age (when D&D settings usually are).
You can get a rather accurate feel for the strengths and weaknesses of various units relavent to D&D by becoming familiar with Medieval: and Rome:Total War. Reading about it is nice, but nothing beats ordering around armies in a quality simulation.