TomeNET

(6.3) Loot tables, treasure classes                                             
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Also called drop tables, specifying which type of items a monster might drop.
The type, level, quality and use-level of an item may depend on these factors:

-The level of the entity it is dropped by (monster or chest).
 Monsters have a loot table that you can review by pressing ~7. It knows five
 so-called "treasure classes":
 Treasure, combat, magic, tools, junk (see further below).

 Small chests have a higher chance of dropping gold instead of items, while
 larger chests drop more items than gold. Note that items found in chests have
 a high chance of being 'good' aka enchanted (same as DROP_GOOD monster flag).

 Monsters may have DROP_xxx flags that determine if they drop gold, items, how
 many of them, and whether the items have a higher chance to be enchanted or to
 possess ego powers or turn out to be an artifact than usual (those are the
 DROP_GOOD flag for enchantments and especially important the DROP_GREAT flag
 for it becoming and ego item or artifact - also see (6.2) for some tips on
 hunting lower level monsters that have the DROP_GREAT flag).
 Note that unique monsters have a higher chance of dropping enchanted items
 (similar to the effect of the player having more 'Luck').

 A higher chance to turn out 'good' (by luck or by the DROP_GOOD flag or
 equivalent means as described above) will also carry over to become a somewhat
 higher chance to turn out 'great' (ego item or artifact), so for example
 unique monsters and chests don't just have an especially high chance to drop
 enchanted items but will also drop ego/artifact (great) items somewhat more
 often.

-The player's 'Digging' skill, for money mined from terrain features and for
 items discovered from mining - will affect potential item level and quality.
 Amount of gems mined and the level of items discovered will at the same time
 also depend on dungeon floor depth and get limited by it somewhat.

-The floor level (depth) and in the case of acquirement scrolls whether it's
 read on the world surface or not (reading it in a high-level town CAN produce
 the same results as reading it on a dungeon floor of similar level, but will
 not GRANT a high quality, which it does when you read it in a dungeon).

-The event type if it's a reward for some kind of event (for events other than
 extermination orders the use-level is usually zeroed, binding the item to your
 character so it cannot be traded).

-The player's 'winner' state (whether the player has beaten Morgoth or not) and
 the player's 'fallen winner' state (whether the player has died after having
 beaten Morgoth and hence lost the royal title).
 These states are used to determine whether an item is dropped that can only be
 used by winners (WINNERS_ONLY flag) or a random artifact being created
 receives +LIFE bonus (increases hit points) or not. LIFE bonus can also be
 influenced with '!L' inscription on Artifact Creation scrolls.
 The only WINNERS_ONLY items existing in the game are a couple of different
 types of royal armour which melee-oriented characters can utilize to improve
 their tankiness.

-The player's amount of 'Luck' for monster drops and items found by digging,
 see 'LUCK' in (5.8) for details. Luck will increase chances of those items to
 turn out good (enchanted) or even great (ego power or artifact) somewhat more
 often.

-The item's ego powers will increase the item's use-level. If it's an artifact
 it will influence the item's use-level depending on the predefined artifact
 level (for true artifacts) or the artifact's power (for random artifacts).

-The item base type in some special cases (the level may be tied to the
 item's power for certain types of items). For example the use-level of speed
 rings directly and only depends on their +SPEED bonus.

-Whether the item is stolen: Stealing a valuable item has a chance to
 set its level to zero, making it untradable. (There is always a chance for it
 to not get zero'ed though, keeping it tradable, even for the most expensive
 items.)


The most common case by far are items that are dropped by monsters when you
kill them. Neglecting the 'winner' state (that toggles WINNERS_ONLY items and
+LIFE randarts) for now, we are left with three factors which determine the
item that you will find on the floor:

1) The dungeon floor depth (aka dungeon level).
2) The monster race level (the level given in the ~7 monster lore. The actual
   monster level can be higher depending on the depth where you encounter it,
   since monsters get their level boosted if they appear on floors of much
   higher level than their race level).
3) The monster's treasure class table. Each monster type (race) has a table
   of percentage values for these five treasure types, which you can again see
   in the ~7 monster lore. The lore displays the first four classes, while the
   5th is 'hidden' and is the rest chance not covered by the first four:

    -Treasure (dubbed 'Valuables' instead in some ~7 monster spoiler versions):
     Rings, amulets, dragon scale mails, crowns and chests.

    -Combat:
     Weapons, armour (except for boots and cloaks), shields, ammunition.

    -Magic:
     Mage staves, wands, staves, rods, runes, potions, scrolls (except for
     golem command scrolls which fall under 'Junk' category), books,
     parchments.

    -Tools:
     Boots, cloaks, diggers, light sources, flints, food, flasks, trap kits,
     spikes, climbing sets, picklocks,
     backpack safety locks, tarpaulins, mummy wrappings.

    -Junk (rest chance, not covered by the above four categories):
     Skeletons/skulls/bones, bottles, shards of pottery, broken sticks,
     firestones, all golem parts (massive pieces, arms, legs, command scrolls).
     Note: Monsters that don't have any treasure class at all are not set to
           100% junk, but can instead drop any item of all the five classes.

    Example: 'Green naga'.
    A Green naga has 25% chance of dropping 'Combat' loot and 65% chance of
    dropping 'Tools' loot. The remaining 10% chance translates to 'Junk' drops.

The formula for determining the item's level (the item base type level which
determines what kind of item you might get to see; not the actual use-level
that you will see on the item and that affects trading it between characters)
depends on the server configuration but is usually:

(dungeon floor depth + monster race level) / 2
to which (for each item anew) a random tolerance of 0..diff is added, where
'diff' is the difference of above's calculation result to the higher value of
the two 'dungeon floor depth' and 'monster race level'. 'diff' caps at 13.

Note that the highest level items in the game at this time are these two level
115 items: 'Massive Piece of Adamantite' and 'Heavy Ribbed Adamantite Armour'.


Example:

You kill a great wyrm of power on the deepest floor of Angband (-3050 ft), so
floor level is 127 and race level is 85.
(floor + race) / 2 = (127 + 85) / 2 = 106 (the result is always rounded down).
Now the higher of the two (floor and race) is 127. The difference of the result
(106) to 127 is 21. This gets capped at 13 and is the random 'tolerance' for
each item dropped by the wyrm.
The treasure class of the wyrm is 20% treasure and 80% combat.

Let's look at 3 items it drops:

1) 106 + random(0..20) = 106. An unlucky tolerance roll added 0 to the level
   average.
   The item level 106 is still quite high though: The One Ring might actually
   drop since it's level 100 (provided we're not a winner yet, who cannot find
   true artifacts) or a power dragon scale mail (level 100 too) could drop as
   well.
   What cannot drop on this attempt is a Heavy Ribbed Mithril Armour, for
   example, because it is level 110 (see in k_info.txt spoiler file).

2) 106 + random(0..13) = 119. A lucky tolerance roll, we got the full 13 added
   to the level cap of the second item that the wyrm dropped.
   This means that this item could be anything that can possibly drop (from the
   treasure classes 'treasure' and 'combat' that is). So if we have beaten
   Morgoth and hence acquired a royal title, we might see any piece of royal
   armour drop.

3) 106 + random(0..13) = 114. The random tolerance roll of 0..20 turned out to
   be an 8 for this item, closely ruling out Heavy Ribbed Adamantite Armour
   which is level 115, but allowing all other items of the appropriate treasure
   classes of this monster.

Note that there is a small chance that an item is sometimes allowed to vastly
exceed the usual maximum level, an "Out of Depth" (OoD) drop!
This phenomenon accounts for finding Dragon Scale Mail in the Orc Caves and
other such occurances..