Stealth

Version 0.12: This article may not be up to date for the latest stable release of Crawl.

This page refers to the Stealth skill. You may have been looking for the Stealth armour ego.

The Stealth skill is a representation of how well your character understands the art of moving silently. Until your adventurer blunders into the Dungeon and starts killing everything, most monsters spend their time sleeping or wandering about peacefully. It's only after they've caught sight of you that they try to kill you, and by taking precautions to remain unseen, you can avoid dangerous opponents or sneak up on the enemy and initiate combat by stabbing them for incredible amounts of damage. However, understanding the art of stealth is not the only factor in being stealthy; a nimble spriggan dressed in robes will almost always make less noise than a lumbering troll in gold dragon armour. A high Stealth skill would help minimize these handicaps, but in the end knights make terrible ninjas no matter what. As such, most character builds that involve wearing heavy armour ignore stealth entirely, but any other character type can benefit from avoiding fights that aren't in their favor.

Different characters will have different Stealth Scores, based on a wide variety of factors. Likewise, each monster has a Monster Awareness Score. Each time you move or perform an action, all monsters in your line of sight have a (Monster Awareness + 1) / (Your Stealth) chance of spotting you. 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.

Stealth Score

Your character's base Stealth Score equals

(3 × Dexterity) + (Stealth Skill × Stealth Factor)

While your Stealth Skill is your character's understanding of stealth, your Stealth Factor is how naturally stealthy your character's species is:

• Dragon Form: 6
• Trolls, Ogres, Centaurs, Pig Form: 9
• Minotaurs, non-Grey Draconians: 12
• Non-Vampires in Bat Form: 17
• Halflings, Kobolds, Spriggans, Nagas, Felids, Octopodes, Grey Draconians: 18
• Spider Form: 21
• Satiated+ / Thirsty or Very Thirsty / Near Bloodless or Bat Form / Bloodless Vampires: 18 / 19 / 20 / 21
• All other forms: 15

This base Stealth Factor is then modified by the following:

• Statue Form: -3
• Lich Form: +1

Once all of that has been calculated, your total base Stealth Score is then modified by the following:

• Non-flying Felids under the effects of Blade Hands: -50 (You have to walk on those hands, after all)

Your base Stealth Score is then affected by your encumbrance and mental state:

• Encumbered: Divide by 2
• Overloaded: Divide by 5
• Confused: Divide by 3

At this point, other flat modifiers are applied. These look much larger numerically, but bear in mind that modifiers affecting your base Stealth Factor and base Stealth Score may be magnified many times over:

Positive Factors

• Flying or levitating: +10
• Elven cloak and/or boots: +20 each
• Boots/barding of stealth: +50
• Boots of the Assassin: +80 (Fixedart)
• Randarts that enhance stealth: +10 to +79 (randomly determined for each artifact)
• The Shadow card: +80
• Playing a felid: +20
• Nightstalker mutation: +40 per rank
• Thin Skeletal Structure mutation: +25 per rank
• Camouflage mutation: +40 per rank
• Translucent Skin mutation: +20 at rank 2, +40 at rank 3
• Playing a merfolk or octopode while in water: +50
• When under the effect of Umbra: Multiply by roughly 2

Negative Factors

• Wearing armour: -6 × (Evasion Penalty)^2
• Traveling through shallow water: Divide by 2
  • Merfolk, octopodes, nagas, ogres, and trolls receive no water penalty.
• Hooves mutation: -(5 + 5 per rank)
• When under the effect of Silence: -50
• When under the effect of Corona or a divine halo: Divide by roughly 2.5
• Carrying the Orb of Zot: Divide by 3
• When berserking or wielding a lantern of shadows: Stealth = 0

If your Stealth score is < 0, it is treated as though it were 0.

In-Game Display

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"

Monster Awareness

Your chance of going unseen is a ratio between your Stealth Score and each monster's Monster Awareness Score. Monster Awareness is equal to 10, modified as follows:

Positive Factors

• Monster intelligence: +0 for plants/jellies, +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

Negative Factors

• Monsters under the effects of Ensorcelled Hibernation: -10
• If the player is invisible and the monster can't see invisible, or 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.

Other Uses of the Stealth Skill

A high Stealth skill also contributes to your ability to open doors soundlessly. Each time you open a door, the chance of it making noise is:

1 in (Dexterity + (Stealth + Traps)/2)

Therefore, characters with skill in both Stealth and Traps & Doors are much less likely to alert enemies while opening doors than those only skilled in Stealth, but Stealth is by far the more important skill for maintaining secrecy in general.

Stealth Aptitudes

From Dungeon Crawl Stone Soup 0.12 in-game documentation:

At	Ba	Co	DE	Dg	Ds	Dj	Dr	Fe	Fo	Gr	Gh	Gn	Hu	Ko	Mf	Mi	MD	Mu	Na	Op	On	Sp	Te	Tr	Vp	VS
2	0	-1	3	0	0	-1	0	4	3	2	2	8	1	4	2	-1	-2	-1	5	4	-2	5	1	-5	5	3

Grey draconians get +2.