Energy

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

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.

Power is consumed by casting spells, at a rate of 5 times the spell's level. When carrying the Amulet of Yendor, you will expend a random amount from 1 to 3 times the amount you would otherwise. If you fail to cast a spell due to failure rate or confusion, you expend only half the energy required for a success. When you have teleportitis, self-teleporting with ^T always consumes 19 power points (although you need 20 to attempt one), but random teleports consume no power.

Power can be regained slowly over time, quickly by quaffing a non-cursed potion of gain energy or by invoking The Mitre of Holiness, and fully by reading a scroll of charging (even a cursed one) while confused. The potion increases your maximum power by the same amount it does your current power; the scroll does so (by 5d4 points) only if your power is already at maximum when you read it. Eating a newt corpse occasionally raises your current Power by 1-3 points, with the message "You feel a mild buzz". It will always raise your power if your current power is 2/3 or less of your maximum. If this increase puts you over your maximum power, the corpse instead has a 1/3 chance of raising your maximum power by 1.

The rate at which power regenerates over time increases with your Wisdom and Intelligence. If your encumbrance level is stressed or higher it will not regenerate. The Eye of the Aethiopica causes your power to regenerate at a much greater rate than usual (see below).

Energy regeneration

Your energy 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. This regeneration is blocked if your encumbrance is at least Stressed.

If you have energy regeneration (only granted by the carried Eye of the Aethiopica), you will instead regenerate energy every turn.

The amount of energy regenerated each time is between 1 and $\lfloor (\mathit{Wis} + \mathit{Int}) / 15 \rfloor + 1$, which for most spellcasters means 1d2 or 1d3.

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