Spellbook of detect monsters
| spellbook of |
+ detect monsters
|Base price||100 zm|
|Turns to read||1|
|Ink to write||5–9|
|Power cost||5 Pw|
|Equivalent||potion of monster detection|
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 with no opportunity to identify the monsters save by color and glyph. At skilled or expert level it functions as a blessed potion, revealing monsters on the map for 21–60 (more) turns, unless you have over 300 turns of monster detection, in which case only one turn is added.
In the case of long worms, both the monster's head and its tail segments are shown by instantaneous (Unskilled or Basic) detection, but the tail is not by the lasting (Skilled or Expert) effect.
As a level 1 divination spell, detect monsters is useful for training the divination skill, which contains several of the game's most useful non-combat 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, 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 allows you to pinpoint every monster on the level and plan your movements accordingly. It does, however, wear off rather quickly, and needs renewal. Most effective if combined with magic mapping.