# Luck
In addition to the "soft" luck inherent to any game that utilizes randomness, NetHack gives you an explicit Luck statistic that affects many aspects of the game.

Contents

1 Value of Luck
2 Luck timeout
3 Bonus Luck
4 Ways to change your Luck
5 Luck in-game effects

5.1 Natural Luck

6 Strategy
7 Variants

7.1 UnNetHack
7.2 dNetHack

8 Encyclopedia entry
9 References
10 External links

Value of Luck
Luck is the sum of two components: regular Luck and bonus Luck. Regular Luck ranges from −10 to +10, changes with events in the game, and may slowly return to a baseline level (see §&nbsp;Luck timeout below). Bonus Luck, on the other hand, may be −3, 0, or +3, and it is determined by what kind of luckstone (and certain artifacts) you are carrying. Thus the highest possible total Luck is 13, and the lowest possible is −13. A positive value indicates a measure of "good luck" and a negative value indicates "bad luck". However, only a rough idea of your total 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 (only displayed in wizard mode)

1 to 4

lucky

5 to 9

very lucky

≥ 10

extremely lucky

Luck timeout
Luck timeout refers to your regular Luck slowly returning to zero over time, which it will do under normal circumstances. If your Luck is timing out, it is done at a rate of one point per 600 turns (300 if you are carrying the Amulet of Yendor, or if your god is angry).[1] This is counted from the beginning of the game; for example, if you lose one point of Luck on turn 590, you will regain it on turn 600, not on turn 1190.
The baseline level to which it may return is +1 if you most recently started or restored the game during a full moon, −1 if started or restored on Friday the 13th, and 0 if neither or both. A new moon does not affect your Luck at all. These changes in the baseline level do not affect the maximum and minimum values.

The following information pertains to an upcoming version (NetHack 3.7.0). If this version is now released, please verify that it is still accurate, then update the page to incorporate this information.

Killing your Quest leader sets your baseline Luck to -4, adjusted by date and moon phase as above.
Whether your regular Luck will return to its baseline level is controlled by luckstones and certain quest artifacts. The effect of these "Luck items" depends on the number in your main inventory that are blessed, uncursed, and cursed (see table below).

Number of Luck items

Bad Luck

Good Luck

None

Times out

Times out

More cursed than blessed

No timeout

Times out

Equal cursed and blessed (or all uncursed)

No timeout

No timeout

More blessed than cursed

Times out

No timeout

Note that as a special case (which is possibly a bug), the game will consider you to own no Luck items if both the following conditions are true:

You have no luckstones, specifically;
The number of cursed Luck items (other than stones) equals the number of noncursed Luck items.
When this case applies, the effect is identical to owning no Luck items: no bonus Luck, and Luck times out regardless of whether the total is positive or negative.

Bonus Luck
Bonus Luck works in a similar way to the above table, although both blessed and uncursed Luck items (referred to as "non-cursed") have the same effect.

Number of Luck items

Bonus Luck

More cursed than non-cursed

−3 "reduced Luck"

Equal cursed and non-cursed

+3 "extra Luck"

More non-cursed than cursed

+3 "extra Luck"

The same caveats regarding having the same number of cursed as noncursed Luck items and no luckstones apply here as to Luck timeout.

Ways to change your Luck
Regular Luck is adjusted by each of the events described below, and by the timeout described above. It cannot be reduced below −10 or increased above +10. 

Baseline Luck adjustment

Event

+1

Starting or restoring a game during a full moon.

0

Starting or restoring a game during any time when it is neither full moon nor Friday the 13th, or when it is both full moon and Friday the 13th (which cancel each other out).

−1

Starting or restoring a game on Friday the 13th.

Regular Luck adjustment

Event

−2

Break a mirror. (Other glass items have no effect on Luck.)

−n

Breaking n eggs laid by you (at worst −5).

+1

Sitting on a throne (sometimes).

0

Throwing a worthless gem at a unicorn.[2]

−1 to +1 (average 0)

Throwing unknown valuable gem at cross-aligned unicorn.[3]

−3 to +3 (average 0)

Throwing known valuable gem at cross-aligned unicorn.[4]

+1

Throwing unknown valuable gem at co-aligned unicorn.[5]

+2

Throwing named valuable gem at co-aligned unicorn.[6]

+5

Throwing identified valuable gem at co-aligned unicorn.[7]

−1

Hitting a blind floating eye (1 in 500 chance).

−1

Jumping on a Sokoban level before solving the puzzle.

−1

Breaking a boulder in Sokoban before solving the puzzle.

−1

Casting stone to flesh on a Sokoban boulder before solving the puzzle.

−1

Polymorphing a Sokoban boulder before solving the puzzle.

−1

Reading a scroll of earth in Sokoban before solving the puzzle.

−1

Being pulled by a thrown heavy iron ball in Sokoban before solving the puzzle.

−1

Hurtling through the air in Sokoban by throwing something while levitating before solving the puzzle.

−1

Squeezing past a boulder in Sokoban (or walking over one when polymorphed into a giant) before solving the puzzle.

−1

Killing a tame monster.

−1

Killing a peaceful monster (sometimes). See note below.

−2

Killing a peaceful human when you are not chaotic. ("You murderer!")

−5

Killing a co-aligned unicorn.

−5 to −2

Cannibalism (eating your own species), unless an orc or a caveman.

Set to 0

Praying with negative regular Luck (sometimes: "golden glow" boon).

−3

Praying on a cross-aligned 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

Unsuccessfully trying to convert an altar, if you were not converted.

+1

Successfully converting an altar.

−1

Sacrificing at another god's altar.

−1

Kicking another god's altar ("Thou shalt pay, infidel!")

−1

Trying to engrave something on another god's altar (also gives "Thou shalt pay, infidel!")

+2

Sacrificing your own race on your own chaotic altar.

−2

Sacrificing your own race on Moloch's altar.

−5

Sacrificing your own race when you aren't chaotic.

−1

Sacrificing an unidentified cheap plastic imitation of the Amulet of Yendor.

−3

Sacrificing an identified fake Amulet of Yendor.

+1

Sacrificing and feeling that your god is "slightly mollified" when your Luck is negative.

Set to 0

Sacrificing and feeling that your god is "mollified" when your Luck is negative.

+1

Sacrificing and having a "hopeful feeling" when your Luck is negative.

Set to 0

Sacrificing and having a "feeling of reconciliation" when your Luck is negative.

0 to +5

Sacrificing while your god is pleased.

The following information pertains to an upcoming version (NetHack 3.7.0). If this version is now released, please verify that it is still accurate, then update the page to incorporate this information.

Killing your Quest leader gives -20 Luck, effectively setting it to -10 before bonus Luck.
Prior to Nethack 3.6.0, any Luck penalty associated with Sokoban would occur even after solving the puzzle on that level.
Killing a monster has a 50% chance of reducing Luck by one point, if it was peaceful, but not tame, when it died. Attacking such a monster in melee, with a projectile, or with a ray wand or spell will always anger it, even if it dies in one hit, and so the Luck penalty will never be applied. Beam wands and spells, however, only anger the monster if it survives. Note that cancellation can kill clay golems, and polymorph can kill any monster susceptible to system shock. Crushing a peaceful monster in a drawbridge also risks the penalty.

Luck in-game effects
For details about the effect of Luck on event probabilities, see rnl.
Luck has a part in:

Making a monster peaceful by untrapping it
Making a (too heavy to lift) monster peaceful by trying to untrap it ("

<monster> thinks it was nice of you to try.")
Getting an alignment bonus for untrapping a monster
Accidentally setting off a landmine or beartrap that you are trying to set
Having monsters get mad when they are trapped by one of your traps
Setting off a trap you are trying to disarm
Disarming a shooting trap
Having chest traps fail to work (flame fizzles out, etc)
Having chest traps that do work limited to relatively minor effects (especially if you have a unicorn horn)
Getting any result from prayer (except upset gods—Luck &lt; 0 causes this)
Getting help from your god when poorly aligned
Getting a good result from prayer
Getting the full range of bonus results from prayer
Being confronted by a minion of the god of the altar you converted (or tried to)
Causing the gods to be angry when praying in Gehennom
Having angry gods being less fire and brimstone in their approach
Hitting a monster
Hitting a monster with a thrown object
Hitting a monster with an iron ball when it jerks you back (?)
Hitting something with a boomerang without it splintering
Getting good things from thrones (Luck &lt; 0 is sometimes bad, Luck &gt; 0 is sometimes good)
Destroying or getting gold and gems from throne (Luck ≥ 5 maximizes number of gems)
Getting good things from a magic fountain (natural Luck ≥ 0 required; natural Luck ≥ 4 desirable)
Finding secret doors, hidden corridors, and traps
Breaking open a door
Opening a door
Having your objects resist water damage
Blessed metal items resisting rust
Having a wand of wishing succeed (Luck ≥ 0 guarantees this)
Getting what you wish for (Luck ≥ 0 is pretty much essential)
Writing a scroll you don't know
Picking something off the floor by applying your whip
Attempting a teleport spell in need (guaranteed if Luck ≥ 1)
Getting at least 2 identifies from a blessed scroll of identify (Luck &gt; 0)
Having destroyed polymorphed objects create golems
Having a split off long worm remain tame or peaceful
Natural Luck
Natural Luck refers to your Luck without taking the bonus (or penalty) Luck from carrying a luckstone into account. Most effects of Luck include this bonus, but a handful do not and directly check your Luck stat:

Effects of a magic fountain
Getting a wish from a throne
Clones of tame or peaceful monsters remaining tame or peaceful
Anything that checks your Luck for the purpose of changing it, e.g. praying with negative Luck to have it reset to 0.
Strategy
Main article: Luckstone
You can't do any better than one blessed Luck item, 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. Even an uncursed Luck item will be just as good except when your total Luck is negative (which is a rare situation, although not unheard of); and even when it is negative, the luckstone will harm you only on turns on which your Luck would time out (so you can just bag it for those turns). Cursed luckstones should never be kept in main inventory unless doing so is unavoidable.

Variants
UnNetHack
UnNetHack adds an additional artifact, Luck Blade, that affects Luck timeout. In UnNetHack, Luck items greatly slow down Luck timeout rather than stopping it completely. The modified Luck timeout depends on how far your Luck is from your base Luck: the higher or lower your Luck, the less the timeout is slowed. The timeout is calculated every turn, meaning gaining or losing a point of Luck could result in that point timing out immediately. This also means that Luck timeout is no longer necessarily at multiples of 600 turns if your natural Luck has ever been above or below your base Luck.
The modified Luck timeout is calculated by the following formula. Let lnatural be your current natural Luck, lbase be your base Luck, and a be 2 if you have the Amulet or your god is angry with you, or 1 otherwise.
 [8]
Additionally, Archaeologists gain a +1 bonus to base Luck[9] from wearing a fedora. Putting on or taking off the fedora also changes your natural Luck accordingly.

|lnatural − lbase|

Timeout
Time to 0
Time from 9
Time from 10
Time from 11

0
∞
0
168 000
173 000
173 800

1
24 800
24 800
143 200
148 200
149 000

2
24 200
49 000
119 000
124 000
124 800

3
23 200
72 200
95 800
100 800
101 600

4
21 800
94 000
74 000
79 000
79 800

5
20 000
114 000
54 000
59 000
59 800

6
17 800
131 800
36 200
41 200
42 000

7
15 200
147 000
21 000
26 000
26 800

8
12 200
159 200
8 800
13 800
14 600

9
8 800
168 000
0
5 000
5 800

10
5 000
173 000
0
0
800

11
800
173 800
0
0
0

12
600
174 400
0
0
0

If you have the Amulet or your god is angry with you, halve all times in this table.

dNetHack
In dNetHack, luckstones only slow down (600 instead of 300 turns) the loss of good Luck, even when blessed. They still give the usual permanent extra Luck, however.

Encyclopedia entry

"[...]  We'll succeed and you'll get all the fortune you came
seeking."
Jack shook his head dismally.  "You'll be better off without
me," he said.  "I'm nothing but bad luck.  It's because I'm
cursed.  A farmer I met on the way to the city cursed me.  He
said, 'I curse you Jack.  May you never know wealth.  May all
that you wish for be denied you.'"
"What a horrid man," said Eddie.  "Why did he curse you like
that?"
Jack shrugged [...].  "Bad grace, I suppose.  Just because I
shot off his ear and made him jump into a pit full of spikes."

[ the hollow chocolate bunnies of the apocalypse,
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;by Robert Rankin ] 

References

↑ timeout.c in NetHack 3.4.3, line 170

↑ gem_accept in dothrow.c

↑ gem_accept in dothrow.c

↑ gem_accept in dothrow.c

↑ gem_accept in dothrow.c

↑ gem_accept in dothrow.c

↑ gem_accept in dothrow.c

↑ src/timeout.c in UnNetHack 5.3.2, line 226

↑ src/timeout.c in UnNetHack 5.3.2, line 193

External links
http://www.spod-central.org/~psmith/nh/gems-343.txt
http://www.statslab.cam.ac.uk/~eva/nethack/index.html#peaceful

This page is based on a spoiler by Dylan O'Donnell. The original license is:
Redistribution, copying, and editing of these spoilers, with or without modification, are permitted provided that the following conditions are met:

The original contributors to any spoiler must continue to be credited.
Any modifications to the spoiler must be acknowledged and credited.

</monster>