Charging

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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 - 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 will reduce a wand to 0 charges before charging it. A wand of wishing charged the second time will always explode; thus players with a wand of wishing (1:0) should always wrest the last wish (zap the wand repeatedly) instead of charging.

Wands

n^3 / 343
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 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 will deal between 1 to 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 will gain some charges.

Blessed charging picks a number of charges between the wand's natural maximum charges and (the maximum 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 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 picks a number in the same way as blessed charging, but then reduces it to a random value between itself and 1 inclusive.[6] The net result is summarised by the following probability table:

Wand type \ number 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 will explode.[9] (Other wands will glow blue if charged beyond their natural maximum, but suffer no ill effects.[10])

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.[11]

Rings

Rings of 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 ring with positive enchantment has an (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 * enchantment) damage.[12]

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 and tools, cursed charging does not clear a ring's enchantment.)

Tools

All chargeable tools may be recharged any number of times without ill effect, with the exception of magic markers.[13]

For all tools, cursed charging will reduce the number of charges to 0, unless the item itself is blessed.

The Bell of Opening

Blessed charging adds d3 charges to the Bell, and uncursed charging adds 1. The resulting number of charges is then capped at 5.[14]

Tinning kit

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.[15]

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.

Expensive camera

An expensive camera may be recharged, and will follow the same formula as a tinning kit.[16]

Magic marker

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. 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.").[17]

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.[18]

Bag of tricks

A bag of tricks may be recharged. Blessed charging will add 6-15 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.[19]

Can of grease

A can of grease may be recharged, and will follow the same formula as a bag of tricks.[20]

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.[21]

Horn of plenty

A horn of plenty may be recharged, and will follow the same formula as a bag of tricks.[22]

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.[23]

Lamps can also be charged with a potion of oil.

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.[24]

The confused effect only applies to the scroll of charging. Invoking the PYEC while confused should still produce the regular charging effect.

References

This page may need to be updated for NetHack 3.6.0.

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 {{nethack-360}} or {{noversion}} as appropriate.