Horse Barding, Mounted Combat

[austinjimm]

The PHB lists 3 types of barding for horses: leather, chain, and plate. What are the effects of these (and particularly leather barding) on a horse's AC? (Remember, a normal horse with no armor is already AC 7.)

Also, I find no guidance in DMG regarding mounted combat (e.g. general bonuses/penalties, charging, unhorsing, etc.). Is there another AD&D source for this?

[Matthew]

Two places to look for "by-the-book" rulings spring to mind: Unearthed Arcana (horse barding) and Wilderness Survival Guide (mounted combat). You can also look to Chain Mail and Swords & Spells for inspiration, as the AD&D rules borrow from them with regard to mounted combat. Indeed, I think it was on this basis that Foster argued that the +1/−1 combat modifiers ought to be +2/−2, since the former was drawn from the 2d6 based CM system.

[austinjimm]

Thanks, Matthew. I'm surprised there's not a more "Gygaxian" source for the AD&D mounted combat rules. I'd have thought Gary would be all over that. The Wilderness Survival rules for unhorsing an opponent are overly complicated for my game. I'll probably just use my grappling rules for that. I agree with Foster on the +2/-2 rule. I was already thinking that actually.

[AxeMental]

Was visiting my sister for a week up in Tallahassee where she lives on a farm, has 5 horses. The grass isn't in yet and man do these guys eat (about a bail of hay a day fed twice a day, plus grains etc.). Also they need to be blanketed when the temp drops into the 30s or risk some getting sick (which ties onto them) might be because of the region. Then they drink alot of water. I never owned a horse, but wow its tiring just watching.

[austinjimm]

Was visiting my sister for a week up in Tallahassee where she lives on a farm, has 5 horses. The grass isn't in yet and man do these guys eat (about a bail of hay a day fed twice a day, plus grains etc.). Also they need to be blanketed when the temp drops into the 30s or risk some getting sick (which ties onto them) might be because of the region. Then they drink alot of water. I never owned a horse, but wow its tiring just watching.

I was just figuring this out a couple days ago for my OUTDOOR SURVIVAL wilderness game. That is, how much does a horse eat/drink?

Here's my current draft:

Daily Necessity Requirements for Horses: In most terrain types (except desert and perhaps mountain) a horse's daily food requirement can be met by letting the animal graze for 1-2 hours hours before and after the daily movement phase and allowing a full day of grazing every 7th day (during the required rest day for any travelling party). A horse's water requirement varies according to type of horse:

5 gallons/day for a light riding horse,
7 gallons/day for a medium horse,
8 gallons/day for a draft horse,
and 10 gallons/day for a heavy war horse.

Like men, a horse's daily water need can be met by passing through any water hex during the movement phase.

I know, I've suddenly slid this thread from from BTB AD&D to Homebrewed OD&D. Sorry 'bout that.

Anyway, I'm wondering if my take (above) is close to what a real horse travelling for days in the wilderness would require. Anybody here knowledgeable about such things?

[Matthew]

Thanks, Matthew. I'm surprised there's not a more "Gygaxian" source for the AD&D mounted combat rules. I'd have thought Gary would be all over that. The Wilderness Survival rules for unhorsing an opponent are overly complicated for my game. I'll probably just use my grappling rules for that.

I am guessing, but probably he just did not see the need to write them as a distinct subset of the normal combat rules, which is where we see the stuff about lance damage and horse hooves (or rather the PHB weapons tables and MM entry for horses). Alternatively we can surmise they did not feature much in his dungeon based games, but that seems to go against the evidence.

I agree with Foster on the +2/-2 rule. I was already thinking that actually.

As a counterpoint it is worth noting that the +2 to hit for CM beserkers was carried over directly to the AD&D MM entry, so there was a clear precedent in using +1/−1. Personally, I think +2/−2 is too big a jump up, but opinions vary.

[Philotomy Jurament]

I know, I've suddenly slid this thread from from BTB AD&D to Homebrewed OD&D.

You mean AD&D *isn't* home-brewed OD&D?

[austinjimm]

I know, I've suddenly slid this thread from from BTB AD&D to Homebrewed OD&D.

You mean AD&D *isn't* home-brewed OD&D?

I thought that GREYHAWK was home-brewed OD&D, and that AD&D was a rebranding of GREYHAWK in order to give one of the two co-authors of the original game sole control over it.

[austinjimm]

I agree with Foster on the +2/-2 rule. I was already thinking that actually.

As a counterpoint it is worth noting that the +2 to hit for CM beserkers was carried over directly to the AD&D MM entry, so there was a clear precedent in using +1/−1. Personally, I think +2/−2 is too big a jump up, but opinions vary.

Yes, but... Translating plusses from Chainmail to D&D presents a problem in interpreting the relative value of the plus as it transitions from a 2d6 bell curve (Chainmail) to a d20 linear progression (D&D), a certain amount of which must be left to the intuition of the referee, insofar as he deems it (i.e. mountedness) an advantage/disadvantage.

(Please excuse the run-on sentence-- and at least one invented word-- multiple beers.)

[Matthew]

Sure, but translating the 2d6 bell curve to the 1d20 linear progression will not really get you very far, because the base probabilities are themselves derived from completely different operations. That is to say, with a long sword you are always going to need 7, 8, 9, 10 or 11 to not only hit, but kill an opponent in CM. In OD&D/AD&D there are many more factors altering the probabilities. Moreover, in CM the +1/−1 deal is itself a simplification of the mass combat system where each class is "one pip" above the one below in both attack and defence versus that class. To put it another way:

CM

Long Sword versus Plate Armour and Shield: 8.3% (Foot); 16.7% (Horse)
Long Sword versus Plate Armour and No Shield: 16.7% (Foot); 27.8% (Horse)
Long Sword versus Mail Armour and Shield: 27.8% (Foot); 41.7% (Horse)
Long Sword versus Mail Armour and No Shield: 41.7% (Foot); 58.3% (Horse)
Long Sword versus Leather Armour and Shield: 27.8% (Foot); 41.7% (Horse)
Long Sword versus Leather Armour and No Shield: 41.7% (Foot); 58.3% (Horse)
Long Sword versus No Armour and Shield: 41.7% (Foot); 58.3% (Horse)
Long Sword versus No Armour and No Shield: 58.3% (Foot); 72.2% (Horse)

OD&D/AD&D (THAC0 20)

Any Weapon versus Plate Armour and Shield: 15% (Foot); 20 or 25% (Horse)
Any Weapon versus Plate Armour and No Shield: 20% (Foot); 25 or 30% (Horse)
Any Weapon versus Mail Armour and Shield: 25% (Foot); 30 or 35% (Horse)
Any Weapon versus Mail Armour and No Shield: 30% (Foot); 35 or 40% (Horse)
Any Weapon versus Leather Armour and Shield: 35% (Foot); 40 or 45% (Horse) [Add 5% for AD&D]
Any Weapon versus Leather Armour and No Shield: 40% (Foot); 45 or 50% (Horse) [Add 5% for AD&D]
Any Weapon versus No Armour and Shield: 45% (Foot); 50 or 55% (Horse) [Add 5% for AD&D]
Any Weapon versus No Armour and No Shield: 55% (Foot); 60 or 65% (Horse) [Add 5% for AD&D]

The long and short of it is that these are not comparable systems. By the logic presented above a shield should similarly add more than 5% in AD&D, since it reduces the probability of a hit in some cases by more than 15% in CM. Indeed, in the above cases:

No Armour: 58.3% → 41.7% (16.6%)
Leather Armour: 41.7% → 27.8% (13.9%)
Mail Armour: 41.7% → 27.8% (13.9%)
Plate Armour: 16.7% → 8.3% (8.4%)

[sepulchre]

Matthew, wonderful post, I know you have addressed much of this intermittently in previous threads, but it is nice to see the probability differences in the attack matrices of differing editions laid out so succinctly. Thanks.

[Matthew]

Always glad to be of service.