Energy

Your power, or "Pw", is the amount of magical energy you have. For example:

Dlvl:3  $:43  HP:68(68) Pw:13(18) AC:-3  Xp:8/1295 T:2358

The above status line shows a character whose current power is 13 and maximum power is 18.

Uses of energy

The main use of energy is to cast spells. You need 5 times the spell's level of energy to cast a spell. When carrying the Amulet of Yendor, there is an additional random cost. This cost applies only to spellcasting, not to any other expenditure of energy. See spellcasting cost for more details.

Teleportation at will from teleportitis requires 20 energy, but only consumes 19. The usual random teleportation from teleportitis does not use energy.

Certain #monster commands require energy. The breath weapons of dragons, iron golems, winter wolves and hell hounds all cost 15 energy. Summoning help as a werecreature and emitting psychic blasts as a mind flayer both cost 10 energy.

Gaining energy

You normally regain energy slowly over time, unless your encumbrance is Stressed or worse, which blocks normal energy regeneration. Having the Eye of the Aethiopica allows you to regain energy rapidly, even when stressed.

Specific methods

Quaffing a non-cursed potion of gain energy increases your current and maximum energy; a cursed potion decreases them.

#invoke the Mitre of Holiness to regain half the energy you need to reach the maximum, but no more than 120 points.

Reading any scroll of charging while confused recharges your energy to its maximum. If it was already maximum, you gain 5d4 total energy instead. In 3.6.0 or later cursed scroll will reduce energy to 0 without altering the maximum “You feel discharged.”

Eating a newt corpse sometimes increases energy by 1 to 3 points. If this would put you over the maximum, your maximum energy might also increase by 1.

If you trigger a magic trap and it explodes, “Your body absorbs some of the magical energy!” and your maximum energy is increased by 2; your energy is then completely refilled.

Attacking a spellcasting monster with Magicbane has a chance of cancelling it and increasing your current and maximum energy by 1 (“You absorb magical energy!”). Only the cancellation from Magicbane can absorb energy. This effect happens every time the cancellation attack hits, not just the first time, when the monster is actually cancelled.

Lying with a foocubus may increase or decrease your energy.

In older versions of NetHack, the polyself bug could be exploited to increase your maximum energy exponentially. However, this bug was fixed in NetHack 3.6.0 and thus is no longer usable.

Energy regeneration

The rate at which energy regenerates over time increases with your experience level, wisdom, and intelligence. If your encumbrance level is Stressed or higher it will not regenerate.

Your energy normally regenerates every $\lfloor (38 - \mathit{level}) \times 3 / 6 \rfloor$ turns if you are a Wizard, and every $\lfloor (38 - \mathit{level}) \times 4 / 6 \rfloor$ turns for other roles. If you carry the Eye of the Aethiopica, you regenerate energy every turn regardless of role.

The amount of energy regenerated each time is between 1 and $\lfloor (\mathit{Wis} + \mathit{Int}) / 15 \rfloor + 1$, which for most characters means 1d2 or 1d3. Increasing that to 1d4 requires a well-enchanted helm of brilliance since no playable race has Wisdom and Intelligence caps high enough to reach a total of 45.

Number of turns between regenerating energy:

Level	Non-wizard	Wizard
1	24	18
2	24	18
3	23	17
4	22	17
5	22	16
6	21	16
7	20	15
8	20	15
9	19	14
10	18	14
11	18	13
12	17	13
13	16	12
14	16	12
15	15	11
16	14	11
17	14	10
18	13	10
19	12	9
20	12	9
21	11	8
22	10	8
23	10	7
24	9	7
25	8	6
26	8	6
27	7	5
28	6	5
29	6	4
30	5	4

Level gain and starting energy

When you gain a level, both your current and maximum energy are increased based on various factors:

• your role
• your race
• your Wisdom
• your experience level

First, a random number $0 \leq n < \left( \frac{\text{Wisdom}}{2} + \text{role modifier}\right)$ is chosen; your race minimum is then added to the result.

Your role modifier depends on whether your experience level (before the level gain) is lower than a certain cutoff which varies between roles. If it is, apply the "low-XL" modifier; else use the "high-XL" modifier.

The result of this is then multiplied with your energy modifier, which depends on your role, and rounded down.

The final result will be added to both your current and maximum energy.

For a newly created character neither energy modifier nor Wisdom matters: certain magically inclined roles start with a few energy points at random, while others only get one point; all races except Dwarves also get a bonus point or two. See the table below for precise numbers.

Role	Cutoff	low-XL modifier	high-XL modifier	energy modifier	starting
Arc	14	1	1	1	1
Bar	10	1	1	3/4	1
Cav	10	1	1	1	1
Hea	20	1	2	3/2	2-5
Kni	10	1	2	3/2	2-5
Mon	10	2	2	1	3-4
Pri	10	2	2	2	5-7
Rog	11	1	1	1	1
Ran	12	1	1	1	1
Sam	11	1	1	1	1
Tou	14	1	1	1	1
Val	10	1	1	3/4	1
Wiz	12	2	3	2	5-7

Race	minimum gain	starting
Human	2	+1
Elf	3	+2
Dwarf	0	no bonus
Gnome	2	+2
Orc	1	+1

Variants

SLASH'EM

Self-teleport costs 30 points of power.

The energy regeration frequency formula is changed to $\lfloor (45 - \mathit{level}) \times 3 / 6 \rfloor$ turns if you are a Wizard, and every $\lfloor (45 - \mathit{level}) \times 4 / 6 \rfloor$ for all other roles.

FIQHack

There are numerous changes to energy and energy regeneration in FIQHack.

• Monsters and players use the same spellcasting system, which means that monsters use energy to cast spells instead of using a cooldown system. This means they can potentially cast multiple spells in succession if they have enough energy, so high-level spellcasting monsters can do much more damage.

• Wisdom is slightly less important for energy regeneration and experience level is slightly more important. Intelligence is not considered.

• Wizards get a boost of +0.33pw/turn for energy regeneration

• The Eye of the Aethiopica confers +1pw/turn for energy regeneration

• Players can be cancelled, which results in 0 available energy until cured.

External links

• HP and power starting values, level increases, and regeneration in NetHack 3.4.3

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.