Recently I was DMing a game, and my players ran into a giant lizard. After they defeated it, they asked if they could skin the lizard and make it into armor. I basically just made it up on the fly; all that happened was they made a huge mess. What are the rules for skinning animals, if there are any?
There are no official rules for that in 1e. There are hunting and foraging rules in the AD&D Wilderness Survival Guide and nonweapon crafting proficiencies, including Leatherworker, in the AD&D Dungeoneer's Survival Guide, but they do not speak to specifics like amounts of raw material required or the skinning process. Just make it up; sounds like you did fine.
There are rules covering the making of armors in AD&D 2E Fighter's Handbook. They don't include the effects on manufacture of variant sources of leather. It is noted, however, that Hide armor is 2 points better than leather, but has worse penalties to Dex and thief skills...
Variant metal armors are in the AD&D 2E DMG.
Both can easily be used in AD&D 1E.
Since I am using the Core Rules 2.0 Expansion CD's RTF's, I can't give page numbers.
What are the rules for skinning animals, if there are any?
See the section on nonweapon proficiencies in the Dungeoneers Survival Guide, page 26 :
Leatherworker: This proficiency allows a character to tan and treat leather, and to make clothing and other leather objects. The character can make leather armor, as well as backpacks, saddle- bags, saddles, and all sorts of harnesses.
While none of the nonweapon proficiency skills explicitly covers the act of skinning the animal, it would not be a far stretch to say that to "tan and treat leather" would include getting the hide off the animal in question. It would also be fair to say that skinning an animal would be a part of the hunting skill. Details for the hunting skill can be found in the Wilderness Survival Guide, page 15. Again, it does not explicitly say it covers the act of skinning but what good is being able to hunt the game if you don't know how to clean/field dress it.
The mechanics of nonweapon proficiencies are simple enough. As seen in the Wilderness Survival Guide, page 11 :
Success and Failure
Unlike a weapon proficiency, the possession of a nonweapon proficiency does not always mean that the character can realize the benefits of having a certain skill. On some occasions, depending upon the particular proficiency or the circumstances surrounding the use of the proficiency, it is necessary for a character to make a successful Proficiency Check in order to be able to use the skill.
A Proficiency Check is accomplished in the same way as an Ability Check. The player rolls 1d20, applies modifiers (if any) to the result, and compares that number to the character’s score in the Appropriate Ability for the proficiency being used. If the modified die-roll result is less than or equal to the score of the Appropriate Ability, the Proficiency Check is successful. (In certain circumstances, the Dungeon Master will make a Proficiency Check die roll instead of the player, and he may or may not reveal to the player the result of the attempt. See the description of the direction sense proficiency for an example of this exception; the Dungeon Master may declare other exceptions of this sort when he deems it appropriate.)
Any unmodified die roll of 19 or 20 on a Proficiency Check indicates automatic failure, regardless of modifiers that would otherwise bring the result down into the range needed for success. Also, for the purpose of a Proficiency Check, any ability score greater than 18 is treated as a score of 18. This means that a character with an Appropriate Ability score of 18 or greater must always make a successful Proficiency Check without the aid of any beneficial modifiers, and that even a character with an Appropriate Ability score of 18 or greater has at least a 10% chance (2 in 20) of failing any Proficiency Check he attempts.
In the case of leather working the check is against INT.
I will note that the section for success and failure of nonweapon proficiencies in the Dungeoneers Survival Guide, page 23, is not correct (the logic in the section detailing check rolls is reversed) and the one in the Wilderness Survival Guide, page 11, should be used as the check roll logic is correctly stated there.
I've had a Quick dig around my books and the Armorer non-weapon proficiency on page 52 of Oriental Adventures says that the character can make all the armor types in the OA book, and from any other AD&D book if they have a piece to copy from but they have to do it at a -2.
Skinning you can just run from the survival non-weapon proficiency
From the D20SRD:
Armorsmiths can work with the hides of dragons to produce armor or shields of masterwork quality. One dragon produces enough hide for a single suit of masterwork hide armor for a creature one size category smaller than the dragon. By selecting only choice scales and bits of hide, an armorsmith can produce one suit of masterwork banded mail for a creature two sizes smaller, one suit of masterwork half-plate for a creature three sizes smaller, or one masterwork breastplate or suit of full plate for a creature four sizes smaller. In each case, enough hide is available to produce a small or large masterwork shield in addition to the armor, provided that the dragon is Large or larger.
I'd read that as you are able to use mundane Lizard scales to create mundane armor. I'd follow the same guidelines. Dragonhide makes masterwork armor, and I think that would be because dragons are innately magical. I'd say nonmagical animals would make regular (not masterwork) armor, but for simplicity's sake, I'd use the same size guidelines for dragonhide above.
If you are trying to get a set of armor for a Medium sized PC, you would need a Large lizard for Hide armor, Huge for Banded Mail armor, Gargantuan for Half Plate armor, and Colossal for Full Plate armor. I'm striking out on finding a stat-block for the Giant Lizard on Google, However, I'd rule that whatever size of tanned leather you need, you could substitute 4 hides of the next smaller size. (so 1 Colossal hide would be about equal to 4 Gargantuan, 16 Huge, 64 Large, 256 Medium, 1024 Small, 4096 Tiny, 16384 Diminutive, and 65536 Fine sized hides).
EDIT: The above should help with how much skin to make armor of various thickness. As for knowing how to make the armor, you will need:
- Not sure for 1e
- the Armorer Nonweapon Proficiency in AD&D 2e
- the Craft(Armorsmithing) skill in 3e/3.5e/Pathfinder
- I'm unfamiliar with 4e.
If you look in Table 36 (Players Handbook) you will find a secondary skill for
Leather worker Brackets (skinning, tanning).
Any hide should be worked as a form of leather, especially if your making high quality suits and armor.