CAVEAT: I'm not sure how this matches up to published adventures, but it works well enough for me. Also, apologies for the crappy formatting.
RANDOM ARMOR DETERMINATION
When characters discover a random suit of armor, the DM can roll on the following chart to determine what type of armor it actually is. If the armor is specifically light, medium or heavy, specific charts for each category are provided.
RANDOM ARMOR (Any)
d% Roll --- Armor Type
01-08 Breastplate
09-18 Chain mail
19-25 Chain shirt
26-30 Half plate
31-37 Hide
38-47 Leather
48-50 Padded
51-60 Plate
61-67 Ring mail
68-72 Scale mail
73-87 Shield
88-94 Splint
95-00 Studded leather
RANDOM ARMOR (Light)
d% Roll --- Armor Type
01-50 Leather
51-63 Padded
64-00 Studded leather
RANDOM ARMOR (Medium)
d% Roll --- Armor Type
01-25 Breastplate
26-46 Chain shirt
47-62 Half plate
63-83 Hide
84-00 Scale mail
RANDOM ARMOR (Heavy)
d% Roll --- Armor Type
01-30 Chain mail
31-62 Plate
63-81 Ring mail
82-00 Splint
RANDOM WEAPON DETERMINATION
When characters discover a random magical weapon, the DM can use the following charts to determine exactly what type of weapon it is. In other cases, a weapon might specify that it is a sword, axe, any melee or any ranged. Specific charts follow for axes, swords, and ranged weapons; if it is “any melee”, roll on the Random Weapon (Any) charts and simply re-roll ranged weapons.
RANDOM WEAPON (Any)
First, determine which of the following charts to roll upon (50% chance of either). Then, roll 1d12+1d8 to determine the specific weapon involved.
d12 + d8 --- Random Weapon --- d12 + d8 --- Random Weapon
2 Club --- 2 Blowgun
3 Trident --- 3 Pike
4 Lance --- 4 Sling
5 Light Hammer --- 5 War Pick
6 Light Crossbow --- 6 Warhammer
7 Javelin --- 7 Heavy Crossbow
8 Mace --- 8 Maul
9 Greataxe --- 9 Rapier
10 Longsword --- 10 Shortsword
11 Greatsword --- 11 Longbow
12 Dagger --- 12 Battleaxe
13 Spear --- 13 Handaxe
14 Glaive --- 14 Scimitar
15 Flail --- 15 Shortbow
16 Halberd --- 16 Morningstar
17 Hand Crossbow --- 17 Quarterstaff
18 Greatclub --- 18 Dart
19 Whip --- 19 Sickle
20 Net --- 20 Other exotic
RANDOM AXE
d% Roll --- Axe Type
01-30 Battleaxe
31-70 Greataxe
71-80 Halberd
81-00 Handaxe
RANDOM SWORD
d% Roll --- Sword Type
01-25 Greatsword
26-50 Longsword
51-70 Rapier
71-80 Scimitar
81-00 Shortsword
RANDOM RANGED WEAPONS
d% Roll --- Weapon Type
01-05 Blowgun
06-12 Dart
13-22 Hand crossbow
23-36 Heavy crossbow
37-48 Light crossbow
49-71 Longbow
72-76 Net
77-89 Shortbow
90-00 Sling
RANDOM AMMUNITION
d% Roll --- Ammunition Type
01-60 Arrow
61-90 Bolt
91-00 Bullet