Griffith Dragonlake said:
And more importantly the effect of helms! You, Gary are the only author I have found who rightly said that intelligent opponents attack the head 50% of the time and that low or non-intelligent opponents have a 1/3 chance.
I should think that any opponent would try for a strike on the unprotected head. Mosquitoes and horseflies know to look for the most exposed area to bite, so anything from that level of intelligence or higher should be smart enough to do likewise. The only catch is, dumb animals make it a point to protect their most exposed areas as much as possible, especially the head.
My experience in the SCA confirms all that you wrote about weapons and helms. Ever since 1979 when I read that note in the DMG I have enforced the rule on PCs not wearing helms. Basically I created a matrix indexing their helm AC and their body AC. Not wearing a helm will get your AC bonus cut in half. Not a smart thing when fighting Against the Giants!
I came up with an alternate way of handling head protection:
http://www.dragonsfoot.org/forums/viewtopic.php?t=19963&start=0
The official rule is that if a PC is wearing armor, but no head protection, then intelligent opponents may strike at the AC 10 noggin. That's fine as far as it goes, but I think I have a way to handle head protection that keeps things simple AND takes into account the fact that dumb monsters and animals should also find a bare head too good to pass up.
My solution is to find out what kind of protection the character has on his head (if any) and average it with the armor he is wearing, drop all fractions. If the average is greater or lesser than the base AC of the armor then the Armor Class goes up or down accordingly by
ONE POINT.
Type of Head Protection(AC)
None (10)
Padded/ Leather (8) *
Studded/Ring/Hide/Skullcap (7) +
Open Helmet/Mail Coif (6) #
Helmet/Scale or Lamellar Coif (5) ++
Helm/Bascinet (3) **
Great Helm/Tournament Helm (2)
* includes padded or leather coifs, thick cloth headwear, etc.
+ the skullcap is either a small helmet that only covers the top of the head or is an open helmet made of weaker materials than metal, such as boiled leather
# open helmet refers to either a basic Spagenhelm or other simple helmets with little or no protection for the face, sides or back of the head or is a regular helmet made of weaker materials
++ this includes the closed-face Spagenhelm, later model Roman helmets, Vendel-era and similar helmets that offer substantial, but not total defense for the face, sides and back of the head
** assumes the face plate is closed, otherwise treat as a regular helmet
This way of handling it keeps combat abstract (no hit locations to worry about, nor any hassle over whether a creature is smart enough to go for the head) while giving an incentive for PCs who can wear helmets or other head protection to do so.