Gems, stones, and luck in NetHack 3.4

gems-343.html Last edited 2004-11-12 for NetHack 3.4.3
Compiled for 3.2.2 by Kevin Hugo.
Updated for 3.4.3 by Dylan O'Donnell <psmith@spod-central.org>.
HTML Conversion by Kate Nepveu <knepveu@steelypips.org>; HTML re-synchronized 2005-08-29 by Dan Fabulich.

Contents

Valuable gems COST WGT PROB ENGR COLORS
dilithium crystal $4500 1 28* soft white
diamond 4000 1 25* hard white
ruby 3500 1 22* hard red
jacinth 3250 1 19* hard orange
sapphire 3000 1 16* hard blue
black opal 2500 1 13* hard black
emerald 2500 1 10* hard green
turquoise 2000 1 7* soft green, blue
aquamarine 1500 1 1* hard green, blue
citrine 1500 1 4* soft yellow
amber 1000 1 1* soft yellowish brown
topaz 900 1 1* hard yellowish brown
jet 850 1 1* soft black
opal 800 1 1* soft white
chrysoberyl 700 1 1* soft yellow
garnet 700 1 1* soft red
amethyst 600 1 1* soft violet
jasper 500 1 1* soft red
fluorite 400 1 1* soft green, blue, white, violet
jade 300 1 1* soft green
agate 200 1 1* soft orange
obsidian 200 1 1* soft black
Worthless gems COST WGT PROB ENGR COLORS
black glass 0 1 76 soft black
blue glass 0 1 77 soft blue
green glass 0 1 77 soft green
orange glass 0 1 76 soft orange
red glass 0 1 77 soft red
violet glass 0 1 77 soft violet
white glass 0 1 77 soft white
yellow glass 0 1 77 soft yellow
yellowish brown glass 0 1 77 soft yellowish brown
Stones COST WGT PROB ENGR COLORS
luckstone 60 10 10 soft gray stone
touchstone 45 10 8 soft gray stone
flintstone 1 10 10 soft gray stone
loadstone 1 500 10 soft gray stone
rock 0 10 100 soft rock

Gems and stones are listed above by category, then by decreasing price. The COST field denotes the base price of each item. WGT specifies the weight (100 zorkmids weighs 1).

Gems comprise 8% of all randomly-generated items in the main dungeon, 18% in containers, 0% on the Rogue level, and 10% in hell. PROB is the relative probability of each subtype, except for those marked with an asterisk (valuable gems); the figures so marked instead represent the first level on which the gems can occur (this limitation only applying to the main dungeon, and these restrictions are only reviewed when creating a new level). Permissible valuable gems have roughly equal probabilities of being generated among themselves, always set such that the total for the category as a whole is 171.

Loadstones are always generated cursed (except potentially in containers), all others are uncursed. Rocks appear in piles of 6 to 11. Valuable gems, worthless gems, touchstones, and flint stones have a 1/6 chance of appearing in a pile of 2.

The ENGR field denotes how the gem appears when you attempt to engrave with it (see below). COLORS specifies the possible appearance of the gem. If more than one color is possible, then one will be randomly chosen for the appearance.

Identifying stones

There are five different types of non-gem stones, and four of them are indistinguishably gray.

rock
Rocks are immediately identified on examination, and pose little difficulty or challenge to the adventurer. They make a cheap and usually plentiful source of ammunition, should you lack or wish to conserve other ranged attacks. ("Good ol' rock. Nothing beats that." -- Bart Simpson)
touchstone
Touchstones are most readily distinguished by their effect when rubbed with something hard, such as an iron weapon; they will make a "scritch, scritch" sound. Their primary use is rubbing them with other gems and stones (and, once identified, this is all they _can_ be used for); if blessed (or also if uncursed, for Archeologists and gnomes), the object rubbed with will be identified. The complete table of results that distinguish them is as follows:
GRAY STONE GEM GLASS HARD RING
good touchstone ID ID scritch streak
bad touchstone streak scratch scritch streak
other gray stone cscratch cscratch scratch cscratch

where "streak" denotes coloured streaks, "scratch" uncoloured scratch marks, "cscratch" coloured scratch marks, and "scritch" the sound "scritch scritch".

Other types of object may produce coloured streaks or scratches, but will not provide any further useful information.

Note that being rubbed on a cursed touchstone may shatter gems or rocks (but not other gray stones).

luckstone
Luckstones can be identified by their effect (see "Luck" below) with the help of enlightenment, by their valuation by shopkeepers, or by the presence of the guaranteed luckstone at the top of a gems cache in the Gnome King's Wine Cellar version of the bottom level of the Gnomish Mines. (Or, indeed, by the Heart of Ahriman being one).
loadstone
As noted above, loadstones are almost always generated cursed; furthermore, they autocurse on being dropped or otherwise leaving the main inventory, and a cursed loadstone cannot be let go of. It is therefore best to identify them while they lie on the ground; kicking them will usually elicit a "Thump!" rather than movement across the floor, but being extremely strong (at least 22 strength; 18/** is not sufficient) while wearing kicking boots or being a Samurai or Monk may allow some movement (watch how far it goes).
flint stone
These exist primarily to make it hard to identify touchstones, loadstones and luckstones, and are best identified by elimination of the other three. They have few special properties, but do inflict somewhat more damage than other stones or gems when used as sling ammunition.

Identifying gems

(Quoted in part from the spoiler "gems" by Bryan Butler.)

"I shall, with cultured taste,
Distinguish gems from paste..."
-- Reginald Bunthorne, in Gilbert and Sullivan's "Patience"

There are now nine methods to identify gems: engraving, throwing at unicorns, killing glass golems, spell of stone to flesh, collecting a large number, scrolls or spells of identify, a touchstone, dipping an amethyst in potions of booze, and finding pre-placed gems.

  1. Engraving with gems

    If a gem is listed as "hard" above, then you will see the following message when you attempt to (E)ngrave with the gem:

    "You engrave in the <floor> with the <gem>."

    where <gem> is the appearance of the gem. All hard gems are valuable, although some colors may have more than one possible identity.

    If the gem is "soft," you will see this message:

    "You write in the dust with the <gem>."

    Soft gems may be valuable or worthless, so you will need an additional method to identify these gems.

    In either case, you can abort the engraving process by pressing Escape. If you choose to write a message, it will take one turn per character to engrave. Not all types of floor can be engraved upon. You may choose to #name a gem once you know its hardness (e.g., "soft blue").

  2. Throwing gems at unicorns

    Throwing a gem to a non-tame unicorn can change your luck in one of several ways, depending on whether the gem is worthless or valuable, whether you are the same alignment as the unicorn (white = lawful, gray = neutral, and black = chaotic), and whether the gem type is already identified or named.

    VALUE ALIGN KNOWN ADVERB LUCK CHANGE
    glass other unknown graciously 0
    glass other named (see below*) 0
    glass other identified (see below*) 0
    glass same unknown graciously 0
    glass same named (see below*) 0
    glass same identified (see below*) 0
    gem other unknown hesitatingly -1 to +1
    gem other named hesitatingly -1 to +1
    gem other identified hesitatingly -3 to +3
    gem same unknown gratefully +1
    gem same named gratefully +2
    gem same identified gratefully +5

    In most cases, the message sequence is as follows:

    "The <unicorn> neighs! The <unicorn> catches the <gem>."
    "The <unicorn> <ADVERB> accepts your gift."

    where the color of the unicorn and the color of the gem are appropriate for the situation. <ADVERB> comes from the table above, except where the column has a *, in which case there is a different message sequence:

    "The <unicorn> neighs!"
    "The <unicorn> catches the <glass>."
    "The <unicorn> is not interested in your junk."

    after which the unicorn will promptly drop the "gem".

  3. Killing glass golems

    When a glass golem is destroyed, it leaves behind 2 to 8 worthless pieces of glass (each of which can be any of the colours), and never gems.

  4. Spell of stone to flesh

    The spell of stone to flesh will turn gemstones into meatballs, but leave worthless pieces of glass intact; #name a gem 'valuable' or similar before zapping the spell at it (and rename it afterwards should it be proven untrue), since it won't be around to #name after.

  5. Collecting a large number of gems

    If you wait long enough, you'll accumulate a large number of gems. Since the probabilities of getting worthless pieces of glass are so much higher than getting true gems, you'll acquire them much faster than other gems. So, if you just wait long enough, and look at all of the gems of a certain color that you have, more often than not the gem of which you have the most is the worthless piece of glass. This is a bit risky, and usually takes much more time than other methods.

  6. Scrolls and spells of identify

    You can always use a scroll or spell of identify to determine whether a gem is valuable. You will then recognize all gems of that same type, although you can lose this knowledge from a scroll of amnesia or (master) mind flayer attack. Shopkeepers will buy identified gems based on their full price; this is a good way to get money.

  7. Rubbing on a touchstone

    Being rubbed on a blessed touchstone (or also uncursed for Archeologists, who start with one, and gnomes) will immediately identify any gem, as detailed under "touchstones" above.

  8. Dipping amethysts into potions of booze

    When you dip an amethyst into a potion(s) of booze, the potion will turn into fruit juice ("a-methyst" means not intoxicated). You can use this very special case to identify this type of soft violet gems.

  9. Pre-placed gems

    Certain levels are guaranteed to be generated with diamonds, rubies, emeralds, and amethysts in well-defined positions. Two versions of the bottom level of the Gnomish Mines (the Wine Cellar version and Mimic of the Mines version) contain concealed chambers with these four types of gems and a guaranteed luckstone, together with assorted other * to confuse identification; the third version's are randomly scattered across the level. The four corner rooms of Fort Ludios (if it is reachable in your game) each contain one of these four types of valuable gems. Other levels may also be generated with piles of gems, but their type is not guaranteed, so these levels are not helpful in determining the identity of gems.

Luck

Luck is included here because of luckstones.

Your luck affects many aspects of the game (too many to mention here), and is actually the sum of two components. Base luck changes with events in the game, and may slowly return to a "baseline" level. Bonus luck, on the other hand, is determined by what kind of luckstone (and certain artifacts) you are carrying. Only a rough idea of your luck is given in the enlightenment list; the meaning of the messages is as follows:

TOTAL LUCK MESSAGE
<= -10 extremely unlucky
-9 to -5 very unlucky
-4 to -1 unlucky
0 luck is zero (debug mode only)
1 to 4 lucky
5 to 9 very lucky
>= 10 extremely lucky

Your bonus luck -- and whether your base luck will return to its baseline level -- is controlled by luckstones and certain Quest Artifacts. The effect of these "luckitems" depends on the number in your main inventory that are blessed, uncursed, and cursed (see table below). Note that you can't do any better than one blessed luckitem, so you might as well keep any others in a bag (where they have no effect) as spares in case your main one is cursed.

NUMBER OF LUCK ITEMS BAD LUCK GOOD LUCK BONUS LUCK
None Times out Times out 0 (no message)
More cursed than blessed No timeout Times out  
Equal cursed and blessed No timeout No timeout  
More blessed than cursed Times out No timeout  
More cursed than non-cursed     -3 "reduced luck"
Equal cursed and non-cursed     +3 "extra luck"
More non-cursed than cursed     +3 "extra luck"

When you are enlightened about your luck, you are also told if you have bonus luck and if good/bad luck will not time out.

Base luck is adjusted by each of the events described below. It cannot be reduced below -10 or increased above +10 beyond the baseline. In addition, every 600 turns (or 300 if you have the Amulet of Yendor or have angered your god), your luck will increase by one if it is less than your baseline luck and bad luck times out, and your luck will decrease by one if your luck is greater than your baseline luck and good luck times out. Your baseline luck is +1 if you started or restored the game during a full moon, -1 if started/restored on Friday the 13th, and 0 if neither or both.

BASE ADJ EVENT
+1 Starting or restoring a game during a full moon.
0 Starting or restoring a game during a new moon.
-1 Starting or restoring a game on Friday the 13th.
  NOTE: The above three are reversed before saving.
-2 Break a mirror.
-n Breaking n eggs laid by you (at worst -5).
+1 Sitting on a throne (sometimes).
0 Throwing a worthless gem at a unicorn.
-3 to +3 Throwing valuable gem at cross-aligned unicorn.
+1 Throwing unknown valuable gem at co-aligned unicorn.
+2 Throwing named valuable gem at co-aligned unicorn.
+5 Throwing identified valuable gem at co-aligned unicorn.
-1 Hitting a blind floating eye (1 in 500 chance).
-1 Jumping in Sokoban.
-1 Breaking a boulder in Sokoban.
-1 Casting stone-to-flesh on a Sokoban boulder.
-1 Polymorphing a Sokoban boulder.
-1 Reading a scroll of earth in Sokoban.
-1 Being pulled by a thrown iron ball in Sokoban.
-1 Hurtling through the air in Sokoban due to Newton's 3rd Law.
-1 Walking (as a giant) or squeezing past a Sokoban boulder.
-1 Killing a tame or peaceful (sometimes) monster.
-2 Killing a peaceful human, and you are not chaotic.
-5 Killing a co-aligned unicorn.
-5 to -2 Cannibalism (eating your own species), unless an orc.
Set to 0 Praying with negative base luck (sometimes; "golden glow" boon).
-3 Praying on wrong altar.
-3 Praying before your prayer timeout has expired.
-5 A sacrifice (not your own race) on Moloch's altars in Gehennom.
-3 Being converted by trying to convert an altar.
-1 Otherwise unsuccessful at converting altar.
+1 Successfully converting an altar.
-1 Desecrating another god's altar.
+2 Sacrificing your own race on your own chaotic altar.
-2 Sacrificing your own race on Moloch's altar.
-5 Sacrificing your own race, you aren't chaotic.
-1 Sacrificing an unidentified fake Amulet of Yendor.
-3 Sacrificing an identified fake Amulet of Yendor.
+1 Sacrificing, slightly mollifying your god, negative luck.
Set to 0 Sacrificing, mollifying your god, negative luck.
+1 Sacrificing, having a hopeful feeling, negative luck.
Set to 0 Sacrificing, reconciling, negative luck.
0 to +5 Sacrificing, god happy.

Acknowledgements

Thanks to Bruce Cox for proofreading the original version of this file.
Further corrections and clarifications provided by David Damerell, Rob Ellwood, Yair Friedman, David Grabiner, Adam Kao, Nick Number, and Donald Welsh.


Up to the NetHack Page