# Spellbook of detect monsters

spellbook of  +   detect monsters   

Appearance

random

Abundance

4.37%

Base price

100 zm

Weight

50

Turns to read

1

Ink to write

5–9

Spell type

divination

Level

1

Power cost

5 Pw

Direction

non-directional  

Equivalent

potion of monster detection

In NetHack, the spellbook of detect monsters teaches the detect monsters spell.

Effects
At unskilled or basic skill level, the spell functions as an uncursed potion of monster detection, displaying the monsters of that dungeon level against a black background with no map detail, and allowing you to select monsters with the cursor to identify them; once you end the effect, the monsters revealed by the spell vanish from view.[1] At skilled or expert level it functions as a blessed potion, revealing monsters on the map for 21–60 (more) turns; if you already have over 300 turns of monster detection, only one turn is added.[2]

Strategy
As a level 1 divination spell, it is useful for training the divination skill, which contains several of the game's best utility spells. At low skill, it is not as useful as light, especially if you already have intrinsic telepathy from a floating eye. Once you reach Skilled, however, it becomes quite useful, serving as a superior alternative to blind or extrinsic telepathy. Unlike telepathy, monster detection can reveal brainless monsters, and does so across the entire map. This reveals the location of every monster on the level and lets you plan your movements accordingly. It does, however, wear off rather quickly. It is most effective if combined with magic mapping.

References

↑ src/spell.c in NetHack 3.6.6, line 1161

↑ src/potion.c in NetHack 3.6.6, line 816