Difference between revisions of "Charging"

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{{for|magically improving weapons and armor|scroll of enchant weapon|scroll of enchant armor}}
 
Some [[item]]s, like [[wand]]s, [[magic harp]]s, [[horn of plenty|horns of plenty]], [[brass lantern]]s and the [[Bell of Opening]] are only effective for a finite number of uses. Each potential use is called a '''charge''', and '''charging''' is the process of adding more charges to an item. The most common methods of charging are the [[scroll of charging]] and [[the Platinum Yendorian Express Card]].
 
Some [[item]]s, like [[wand]]s, [[magic harp]]s, [[horn of plenty|horns of plenty]], [[brass lantern]]s and the [[Bell of Opening]] are only effective for a finite number of uses. Each potential use is called a '''charge''', and '''charging''' is the process of adding more charges to an item. The most common methods of charging are the [[scroll of charging]] and [[the Platinum Yendorian Express Card]].
  
Such items are shown with two numbers at the end of their description - '''a wand of magic missile (0:5)''' - the first number is how many times the item has been recharged, and the second is the number of charges remaining. The recharge counter stops at '''(7:y)''', though the item can still be recharged further if applicable. A discharged item is '''(x:0)''', and a canceled item is '''(x:-1)'''.
+
Such items are shown with two numbers at the end of their description when fully [[identification|identified]], e.g. <tt>a wand of magic missile (0:5)</tt>. The first number is how many times the item has been recharged, and the second is the number of charges remaining. The recharge counter stops at <tt>(7:y)</tt>,{{refsrc|read.c|302}} though the item can still be recharged further if applicable. A discharged item is <tt>(x:0)</tt>, and a [[Cancellation|canceled]] item is <tt>(x:-1)</tt>.
  
If you were thinking of magically improving weapons and armor, you want a [[scroll of enchant weapon]] or [[scroll of enchant armor]] instead.
+
Repeated charging is potentially problematic. A [[wand]] charged more than once might explode; this is why nearly all players reduce a wand to 0 charges before charging it. A [[wand of wishing]] charged the second time always explodes; thus [[player]]s with a wand of wishing (1:0) should always [[Wresting|wrest]] the last wish (zap the wand repeatedly) instead of charging.
 
 
Repeated charging is potentially problematic. A [[wand]] charged more than once might explode; this is why nearly all players will reduce a wand to 0 charges before charging it. A [[wand of wishing]] charged the second time will always explode; thus [[player]]s with a wand of wishing (1:0) always wrest the last [[wish]] (zap the wand repeatedly) instead of charging.
 
  
 
== Wands ==
 
== Wands ==
  
If a wand has been recharged at least once before, there is a chance it might explode, destroying itself. A [[wand of wishing]] will always explode if recharged more than once. For other wands, the chance of an explosion is ''n<sup>3</sup>/343'', where ''n'' is the number of times the wand has been recharged before. This is summarised in the following table:<ref>[[read.c#line227]]</ref>
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[[File:NHC-Wand-Charging-Odds.png|thumb|n<sup>3</sup> / 343]]If a wand has been recharged at least once before, there is a chance it might explode, destroying itself. A [[wand of wishing]] always explodes if recharged more than once. For other wands, the chance of an explosion is <tt>n<sup>3</sup>&nbsp;/&nbsp;343</tt>, where <tt>n</tt> is the number of times the wand has been recharged before. This is summarized in the following table:{{refsrc|read.c|227}}
  
 
{| class="prettytable"
 
{| class="prettytable"
Line 19: Line 18:
  
 
And the combined, cumulative probability of working towards maximum charges:
 
And the combined, cumulative probability of working towards maximum charges:
 +
[[File:NHC-Cumulative-Wand-Charging-Odds.png|thumb|Cumulative]]
  
<!-- ' Two charges.
 
100-Percent((342*335)/(343^2))
 
Ans = 2.617106818
 
Round(Ans,2)
 
Ans = 2.62
 
' Three charges.
 
100-Percent((342*335*316)/(343^3))
 
Ans = 10.282815611
 
Round(Ans,2)
 
Ans = 10.28
 
' Four charges.
 
100-Percent((342*335*316*279)/(343^4))
 
Ans = 27.023048266
 
Round(Ans,2)
 
Ans = 27.02
 
' Five charges.
 
100-Percent((342*335*316*279*218)/(343^5))
 
Ans = 53.618147295
 
Round(Ans,2)
 
Ans = 53.62
 
' Six charges.
 
100-Percent((342*335*316*279*218*127)/(343^6))
 
Ans = 82.826544334
 
Round(Ans,2)
 
Ans = 82.83
 
-->
 
 
{| class="prettytable"
 
{| class="prettytable"
 
! Times recharged !! 0 !! 1 !! 2 !! 3 !! 4 !! 5 !! 6 !! 7
 
! Times recharged !! 0 !! 1 !! 2 !! 3 !! 4 !! 5 !! 6 !! 7
 
|-
 
|-
! Cumulative Chance
+
! Cumulative chance
 
| (never) || 0.29% || 2.62% || 10.28% || 27.02% || 53.62% || 82.83% || (always)
 
| (never) || 0.29% || 2.62% || 10.28% || 27.02% || 53.62% || 82.83% || (always)
 
|}
 
|}
  
And thus the expected average, per wand, is 4.62 charges before the wand explodes.
+
And thus the expected average, per wand, is 5.2334 charges before the wand explodes.
 
<!-- ' Linear interpolation.
 
<!-- ' Linear interpolation.
 
Interpolate(L,x,y) = (x*(1-L)+y*L)
 
Interpolate(L,x,y) = (x*(1-L)+y*L)
Line 64: Line 38:
 
Ans = 4.620039683 -->
 
Ans = 4.620039683 -->
  
An exploding wand will deal between 1 and 2(maxhp+1)/3 damage,<ref>[[read.c#line1304]]</ref> so don't risk it if you're below full HP or in a place that isn't safe.
+
An exploding wand deals between <tt>1</tt> and <tt>2(maxhp+1)/3</tt> damage,{{refsrc|read.c|1304}} so don't risk it if you're below full HP or in a place that isn't safe.
  
If the wand does not explode, it will gain some charges.
+
If the wand does not explode, it gains some charges.
  
Blessed charging picks a number of charges between 5 and the wand's natural maximum charges (with all values having equal probability). This is summarised by the following probability table:<ref>[[read.c#line254]]</ref>
+
Blessed charging picks a number of charges between the wand's natural maximum charges and <tt>(max&nbsp;charges&nbsp;&minus;&nbsp;4)</tt> inclusive, with all values having equal probability,{{refsrc|read.c|257|name=charge_target}} excluding wands of wishing for which 3 is always chosen.<ref name="charge_target"/>{{refsrc|read.c|254}} This is summarized by the following probability table:
  
{| class="prettytable"
+
{| class="prettytable" style="text-align: center;"
! Wand type \ number !! 1 !! 2 !! 3 !! 4 !! 5 !! 6 !! 7 !! 8 !! 9 !! 10 !! 11 !! 12 !! 13 !! 14 !! 15
+
! rowspan=2|Wand type !! colspan=15|Number chosen
 +
|-
 +
| 1 || 2 || 3 || 4 || 5 || 6 || 7 || 8 || 9 || 10 || 11 || 12 || 13 || 14 || 15
 
|-
 
|-
 
! [[wand of wishing]]
 
! [[wand of wishing]]
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|-
 
|-
 
! directional
 
! directional
| || || || || 25% || 25% || 25% || 25% || || || || || || ||
+
| || || || 20% || 20% || 20% || 20% || 20% || || || || || || ||
 
|-
 
|-
 
! non-directional
 
! non-directional
| || || || || 9.09% || 9.09% || 9.09% || 9.09% || 9.09% || 9.09% || 9.09% || 9.09% || 9.09% || 9.09% || 9.09%
+
| || || || || || || || || || || 20% || 20% || 20% || 20% || 20%
 
|}
 
|}
  
Uncursed charging picks a number in the same way as blessed charging, but then reduces it to a random value between itself and 1 inclusive. The net result is summarised by the following probability table:
+
Uncursed charging chooses a number in the same way as blessed charging, then reduces the number to a value between 1 and the chosen number inclusive.{{refsrc|read.c|258}} The net result is summarized by the following probability table:
  
{| class="prettytable"
+
{| class="prettytable" style="text-align: center;"
! Wand type \ number !! 1 !! 2 !! 3 !! 4 !! 5 !! 6 !! 7 !! 8 !! 9 !! 10 !! 11 !! 12 !! 13 !! 14 !! 15
+
! rowspan=2|Wand type !! colspan=15|Number chosen
 +
|-
 +
| 1 || 2 || 3 || 4 || 5 || 6 || 7 || 8 || 9 || 10 || 11 || 12 || 13 || 14 || 15
 
|-
 
|-
 
! [[wand of wishing]]
 
! [[wand of wishing]]
Line 92: Line 70:
 
|-
 
|-
 
! directional
 
! directional
| 15.9% || 15.9% || 15.9% || 15.9% || 15.9% || 10.9% || 6.7% || 3.1% || || || || || || ||
+
| 17.69% || 17.69% || 17.69% || 17.69% || 12.69% || 8.69% || 5.36% || 2.5% || || || || || || ||
 
|-
 
|-
 
! non-directional
 
! non-directional
| 11.2% || 11.2% || 11.2% || 11.2% || 11.2% || 9.4% || 7.9% || 6.6% || 5.5% || 4.4% || 3.5% || 2.7% || 2.0% || 1.3% || 0.6%
+
| 7.79% || 7.79% || 7.79% || 7.79% || 7.79% || 7.79% || 7.79% || 7.79% || 7.79% || 7.79% || 7.79% || 5.97% || 4.30% || 2.76% || 1.33%
 
|}
 
|}
  
For both blessed and unblessed charging, the wand's number of charges is set to the chosen value. If the wand already has that many charges (or more), it instead gains one charge. If this extra charge brings a wand of wishing to more than 3 charges, it will explode. (Other wands will glow blue if charged beyond their natural maximum, but suffer no ill effects.)<ref>[[read.c#line262]]</ref>
+
For both blessed and unblessed charging, the wand's number of charges is set to the chosen value.{{refsrc|read.c|260}} If the wand already has that many charges (or more), it instead gains one charge.{{refsrc|read.c|261}} If this extra charge brings a wand of wishing to more than 3 charges, it explodes.{{refsrc|read.c|262}} (Other wands glow blue if charged beyond their natural maximum, but suffer no ill effects.{{refsrc|read.c|266}})
  
Cursed charging will set the wand's number of charges to 0, unless the wand itself is blessed. This happens even if the wand was at '''(x:-1)''', i.e. it was cancelled.<ref>[[read.c#line224]]</ref>
+
Cursed charging sets the wand's number of charges to 0, unless the wand itself is blessed. This happens even if the wand was at <tt>(x:-1)</tt>, i.e. it was canceled.{{refsrc|read.c|224}}
  
 
== Rings ==
 
== Rings ==
  
[[Ring]]s of [[ring of adornment|adornment]], [[ring of gain strength|gain strength]], [[ring of gain constitution|gain constitution]], [[ring of increase accuracy|increase accuracy]], [[ring of increase damage|increase damage]], and [[ring of protection|protection]] may be charged to alter their enchantment.
+
[[Ring]]s with numerical enchantment levels&mdash;namely, [[ring of adornment|adornment]], [[ring of gain strength|gain strength]], [[ring of gain constitution|gain constitution]], [[ring of increase accuracy|increase accuracy]], [[ring of increase damage|increase damage]], and [[ring of protection|protection]]&mdash;may be charged to alter their enchantment.
  
Before the ring is charged, there is a chance it might explode. A ring with positive enchantment has a (enchantment before charging) in 7 chance of exploding. A ring of +7 or greater, or -5 or less, will always explode when charged. An exploding ring will deal between 1 and ''(3&nbsp;*&nbsp;enchantment)'' damage.<ref>[[read.c#line270]]</ref>
+
Before the ring is charged, there is a chance it might explode. A +''n'' ring has an {{frac|''n''|7}} probability of exploding if 0 < ''n'' < 7, or a 100% probability if ''n'' &le; -5 or ''n'' &ge; 7. An exploding ring deals 1d(3&times;|''n''|) damage to the player.{{refsrc|read.c|270}}  If the ring does not explode, its enchantment is updated according to the scroll's BUC, with blessed charging adding 1&ndash;3 points, uncursed charging adding 1, and cursed charging subtracting 1&ndash;2 points.
 
 
If the ring does not explode, its enchantment will be updated. Blessed charging will add 1-3 points, uncursed charging will add 1, and cursed charging will subtract 1-2 points. (Unlike [[#Wands|wands]] and [[#Tools|tools]], cursed charging does not clear a ring's enchantment.)
 
  
 
== Tools ==
 
== Tools ==
  
All chargeable [[tool]]s may be recharged any number of times without ill effect, with the exception of [[#Magic_marker|magic marker]]s.<ref>[[read.c#line300]]</ref>
+
All chargeable [[tool]]s may be recharged any number of times without ill effect, with the exception of magic markers.
  
For all tools, cursed charging will reduce the number of charges to 0, unless the item itself is blessed.
+
For all tools, cursed charging reduces the number of charges to 0, unless the item itself is blessed, in which case nothing will happen.
  
=== The Bell of Opening ===
+
{|class="wikitable"
 
+
!Tool !! Uncursed charging adds !! Blessed charging adds !! Maximum !! Notes
Blessed charging adds ''d3'' charges to the [[Bell of Opening|Bell]], and uncursed charging adds 1. The resulting number of charges is then capped at 5.<ref>[[read.c#line306]]</ref>
+
|-
 
+
| [[Bell of Opening]] || 1 || d3 || 5 ||
=== Tinning kit ===
+
|-
 
+
| [[tinning kit]], [[expensive camera]], [[magic marker]] || 10-20 || 15-30 || 127 ||
A [[tinning kit]] may be recharged. Blessed charging will add 15-30 charges. If the resulting number of charges is less than 50, it will be increased to 50; if it is greater than 50 but less than 75, it will be rounded up to 75.<ref>[[read.c#line313]]</ref>
+
* If blessed charging and charges are greater than 50 but less than 75, round up to 75.
 
+
* If blessed or uncursed charging and charges are less than 50, round up to 50.
Uncursed charging will add 10-20 charges, rounding up to 50. For both blessed and uncursed charging, the final number of charges is capped at 127.
+
* Magic markers that have already been recharged will not charge again, and if 3 or fewer charges remain on an already-recharged marker, they are lost.
 
+
|-
=== Expensive camera ===
+
| [[crystal ball]] || 1 || set to 6 || 5 (unless blessed charging) ||
 
+
|-
An [[expensive camera]] may be recharged, and will follow the same formula as a [[#Tinning_kit|tinning kit]].<ref>[[read.c#line315]]</ref>
+
| [[bag of tricks]], [[can of grease]], [[horn of plenty]] || 1-5 || 6-15 if fewer than 10 charges left; else 5-10 || 50 ||
 
+
|-
=== Magic marker ===
+
| [[magic flute]], [[magic harp]], [[frost horn]], [[fire horn]], [[drum of earthquake]] || d4 || 2d4 || 20 ||
 
+
|-
A [[magic marker]] may be recharged, but only once. A marker that has not been recharged before will follow the same formula as a [[#Tinning_kit|tinning kit]]. If the marker has been recharged, charging will not be effective; furthermore, if 3 or fewer charges remain, they will be lost (''"Your marker seems permanently dried out."'').<ref>[[read.c#line312]]</ref>
+
| [[oil lamp]], [[brass lantern]] || 750 || 1500 || 1500 || Dipping an oil lamp in a [[potion of oil]] also fills it to 1500, though this is not magical charging.
 
+
|}
=== Crystal ball ===
 
 
 
A [[crystal ball]] may be charged. Blessed charging will set the ball's charges to 6. Uncursed charging will add 1, up to a maximum of 5.<ref>[[read.c#line372]]</ref>
 
 
 
=== Bag of tricks ===
 
 
 
A [[bag of tricks]] may be recharged. Blessed charging will add 10-15 charges if 10 or fewer remain, or 5-10 charges otherwise. Uncursed charging will add 1-5 charges. For both of these, the final number of charges will not exceed 50.<ref>[[read.c#line385]]</ref>
 
 
 
=== Can of grease ===
 
 
 
A [[can of grease]] may be recharged, and will follow the same formula as a [[#Bag_of_tricks|bag of tricks]].<ref>[[read.c#line386]]</ref>
 
 
 
=== Magical instruments ===
 
 
 
The [[magic flute]], [[magic harp]], [[frost horn]], [[fire horn]], and [[drum of earthquake]] may all be charged. Blessed charging will add ''2d4'' charges, to a maximum of 20. Uncursed charging will add ''d4'' charges, to a maximum of 20.<ref>[[read.c#line400]]</ref>
 
 
 
A [[horn of plenty]] may be recharged, and will follow the same formula as a [[#Bag _of_tricks|bag of tricks]].<ref>[[read.c#line384]]</ref>
 
 
 
=== Lamps ===
 
 
 
An [[oil lamp]] or [[brass lantern]] may be recharged. Blessed charging will fill a lamp to its maximum of 1500 turns. Uncursed charging will add 750 turns, to a maximum of 1500. Cursed charging will reduce the number of turns to 0, unless the lamp itself is blessed.<ref>[[read.c#line352]]</ref>
 
 
 
Note that lamps can also be charged with a [[potion of oil]]. Unlike oil, however, regular charging has no ill effect on a [[magic lamp]].
 
  
 
== Yourself ==
 
== Yourself ==
  
If you read a [[scroll of charging]] while [[confused]], you will not get the usual charging effect.  Instead, your own [[energy]] is replenished to its maximum. If it was already at maximum, the maximum is increased by ''5d4'', and your current energy is increased to the new maximum.<ref>[[read.c#line1057]]</ref>
+
If you read a [[scroll of charging]] while [[confused]], your [[energy]] is replenished to its maximum. If it was already at maximum, the maximum is increased by ''5d4'', and your current energy is increased to the new maximum.{{refsrc|read.c|1057}}
  
Note that this special outcome only applies to the scroll of charging. Invoking the PYEC while confused should still produce the regular charging effect.
+
The confused effect only applies to the scroll of charging. Invoking [[the Platinum Yendorian Express Card]] while confused still produces the regular charging effect.
  
 
== References ==
 
== References ==
Line 170: Line 123:
 
{{featured}}
 
{{featured}}
 
[[Category:Strategy]]
 
[[Category:Strategy]]
 +
{{nethack-343|offset=1}}

Latest revision as of 06:45, 3 August 2020

For magically improving weapons and armor, see scroll of enchant weapon and scroll of enchant armor.

Some items, like wands, magic harps, horns of plenty, brass lanterns and the Bell of Opening are only effective for a finite number of uses. Each potential use is called a charge, and charging is the process of adding more charges to an item. The most common methods of charging are the scroll of charging and the Platinum Yendorian Express Card.

Such items are shown with two numbers at the end of their description when fully identified, e.g. a wand of magic missile (0:5). The first number is how many times the item has been recharged, and the second is the number of charges remaining. The recharge counter stops at (7:y),[1] though the item can still be recharged further if applicable. A discharged item is (x:0), and a canceled item is (x:-1).

Repeated charging is potentially problematic. A wand charged more than once might explode; this is why nearly all players reduce a wand to 0 charges before charging it. A wand of wishing charged the second time always explodes; thus players with a wand of wishing (1:0) should always wrest the last wish (zap the wand repeatedly) instead of charging.

Wands

n3 / 343

If a wand has been recharged at least once before, there is a chance it might explode, destroying itself. A wand of wishing always explodes if recharged more than once. For other wands, the chance of an explosion is n3 / 343, where n is the number of times the wand has been recharged before. This is summarized in the following table:[2]

Times recharged 0 1 2 3 4 5 6 7
Chance of exploding (never) 0.29% 2.33% 7.87% 18.66% 36.44% 62.97% (always)

And the combined, cumulative probability of working towards maximum charges:

Cumulative
Times recharged 0 1 2 3 4 5 6 7
Cumulative chance (never) 0.29% 2.62% 10.28% 27.02% 53.62% 82.83% (always)

And thus the expected average, per wand, is 5.2334 charges before the wand explodes.

An exploding wand deals between 1 and 2(maxhp+1)/3 damage,[3] so don't risk it if you're below full HP or in a place that isn't safe.

If the wand does not explode, it gains some charges.

Blessed charging picks a number of charges between the wand's natural maximum charges and (max charges − 4) inclusive, with all values having equal probability,[4] excluding wands of wishing for which 3 is always chosen.[4][5] This is summarized by the following probability table:

Wand type Number chosen
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
wand of wishing (always)
directional 20% 20% 20% 20% 20%
non-directional 20% 20% 20% 20% 20%

Uncursed charging chooses a number in the same way as blessed charging, then reduces the number to a value between 1 and the chosen number inclusive.[6] The net result is summarized by the following probability table:

Wand type Number chosen
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
wand of wishing 33.3% 33.3% 33.3%
directional 17.69% 17.69% 17.69% 17.69% 12.69% 8.69% 5.36% 2.5%
non-directional 7.79% 7.79% 7.79% 7.79% 7.79% 7.79% 7.79% 7.79% 7.79% 7.79% 7.79% 5.97% 4.30% 2.76% 1.33%

For both blessed and unblessed charging, the wand's number of charges is set to the chosen value.[7] If the wand already has that many charges (or more), it instead gains one charge.[8] If this extra charge brings a wand of wishing to more than 3 charges, it explodes.[9] (Other wands glow blue if charged beyond their natural maximum, but suffer no ill effects.[10])

Cursed charging sets the wand's number of charges to 0, unless the wand itself is blessed. This happens even if the wand was at (x:-1), i.e. it was canceled.[11]

Rings

Rings with numerical enchantment levels—namely, adornment, gain strength, gain constitution, increase accuracy, increase damage, and protection—may be charged to alter their enchantment.

Before the ring is charged, there is a chance it might explode. A +n ring has an n7 probability of exploding if 0 < n < 7, or a 100% probability if n ≤ -5 or n ≥ 7. An exploding ring deals 1d(3×|n|) damage to the player.[12] If the ring does not explode, its enchantment is updated according to the scroll's BUC, with blessed charging adding 1–3 points, uncursed charging adding 1, and cursed charging subtracting 1–2 points.

Tools

All chargeable tools may be recharged any number of times without ill effect, with the exception of magic markers.

For all tools, cursed charging reduces the number of charges to 0, unless the item itself is blessed, in which case nothing will happen.

Tool Uncursed charging adds Blessed charging adds Maximum Notes
Bell of Opening 1 d3 5
tinning kit, expensive camera, magic marker 10-20 15-30 127
  • If blessed charging and charges are greater than 50 but less than 75, round up to 75.
  • If blessed or uncursed charging and charges are less than 50, round up to 50.
  • Magic markers that have already been recharged will not charge again, and if 3 or fewer charges remain on an already-recharged marker, they are lost.
crystal ball 1 set to 6 5 (unless blessed charging)
bag of tricks, can of grease, horn of plenty 1-5 6-15 if fewer than 10 charges left; else 5-10 50
magic flute, magic harp, frost horn, fire horn, drum of earthquake d4 2d4 20
oil lamp, brass lantern 750 1500 1500 Dipping an oil lamp in a potion of oil also fills it to 1500, though this is not magical charging.

Yourself

If you read a scroll of charging while confused, your energy is replenished to its maximum. If it was already at maximum, the maximum is increased by 5d4, and your current energy is increased to the new maximum.[13]

The confused effect only applies to the scroll of charging. Invoking the Platinum Yendorian Express Card while confused still produces the regular charging effect.

References

This page may need to be updated for the current version of NetHack.

It may contain text specific to NetHack 3.4.3. Information on this page may be out of date.

Editors: After reviewing this page and making necessary edits, please change the {{nethack-343}} tag to the current version's tag or {{noversion}} as appropriate.