The Stealth stat determines how likely you are to be detected. While the Stealth skill may be the most direct way to influence this stat, many other factors are equally as or more important.
The measure of a character's stealthiness is its stealth score. A character innately has a base stealth score, which is then modified by various external factors.
Your base stealth score equals:
(3 × Dexterity) + (Stealth skill × 15)
Once you've calculated your base stealth score, an adjustment is made for a special case:
- If you are confused: Divide by 3
Finally, the following flat modifiers are applied. Some of these factors may look much larger numerically than the components of the Base Stealth Score, but a high dexterity and high Stealth skill can result in a very large stealth before any modifiers get involved:
- Boots/barding/ring of stealth: +50
- Randarts that enhance stealth: +50 per +
- Boots of the Assassin: +80 (unrand)
- The Shadow card: +80
- Nightstalker mutation: +50 per rank
- Thin Skeletal Structure mutation: +25 per rank
- Camouflage mutation (octopodes start at rank 1): +50 per rank
- Translucent Skin mutation: +15 per rank
- Playing a merfolk or octopode while in water: +50
- When under the effect of an Umbra: Multiply by roughly 2 (If from Dithmenos, the exact amount is dependent on piety.)
- Bat Form vampire: +50
- Bloodless vampire: +100
- Felid paws: +20 if walking.
- Wearing armour: -2 × (Encumbrance rating)2 / 3
- Traveling through shallow water (unless flying): Divide by 2
- Hooves: -10/-15/-20 for rank 1/2/3, if on the ground.
- When under the effect of Silence: -50, plus an additional penalty based on the ambient noise of your current branch (louder areas penalize you more when silenced than quiet areas)
- Felid under Blade Hands: -50.
- When under the effect of Corona or a Halo: Divide by roughly 2.5
- Carrying the Orb of Zot: Divide by 3
- When berserk: Stealth = 0
- Randarts that reduce stealth: -50 per -
- Worshipping Qazlal: Stealth is multiplied by (200 - min(piety, 160)) / 170, so at piety 160 or higher your stealth is roughly divided by 4.
If your Stealth score is < 0, it is treated as though it were 0.
Although you cannot display your exact Stealth Score, you can get an idea of it by pressing the % or @ buttons. You'll see a description of your stealthiness which correlates to the following Stealth Scores:
- 0- 9: "Extremely unstealthy"
- 10-29: "Very unstealthy"
- 30-59: "Unstealthy"
- 60-89: "Fairly stealthy"
- 90-119: "Stealthy"
- 120-159: "Quite stealthy"
- 160-219: "Very stealthy"
- 220-299: "Extremely stealthy"
- 300-399: "Extraordinarily stealthy"
- 400-519: "Incredibly stealthy"
- 520+: "Uncannily stealthy"
Every monster has their own Monster Awareness score. Each monster has a base awareness of 10, modified as follows:
- Monster intelligence: +0 for plants/jellies/zombies, +4 for insects, +8 for animals, +12 for humanoids, +16 for highly intelligent monsters
- Hit dice: +1 per HD
- Sense invisible: +5
- If the monster is wandering instead of sleeping: +15
- Demons, the undead, holy beings, golems, and plants: +10
- Monsters under the effects of Ensorcelled Hibernation: -10
- If the player is invisible and the monster can't see invisible (or if the monster can sense invisible and the distance between the monster and the player is greater than 4): -75
If Monster Awareness is < 0, it is treated as though it were 0.
Each time you move or perform an action, all monsters in your line of sight have a
(Awareness + 1) / (Your Stealth) chance of spotting you. How fast or slow this action is does not matter; a Naga and Spriggan with the same Stealth score have the same chance per move to be detected. Once they've spotted you, they'll only lose track of you once you've left their line of sight for a while; this occurs much sooner for mindless enemies than for intelligent ones.