The threat level of a monster is an indicator of how difficult or dangerous that monster is. This information is accessible through the monster list at the right side of the screen, or in the monster's descriptions. Ashenzari's monster detection, and Okawaru's piety gain also make use of this information. The game defines four tiers:
|Threat level||Monster's name||Description|
|Trivial||Dark grey||"It looks harmless."|
|Easy||Light grey||"It looks easy."|
|Tough||Yellow||"It looks dangerous."|
|Nasty||Light red||"It looks extremely dangerous."|
It is basically a ratio between the amount of experience points accumulated by the player and how many xp points a monster can provide.
Tension = Monster's XP points / ( 1 + sqrt(Player's XP points / 30)) If Tension is less than 1, Threat = Trivial Else if Tension is less than 6, Threat = Easy Else if Tension is less than 33, Threat = Tough Else, Threat = Nasty