Stealth

Stealth is a property that appears in NetHack, and generally enables a hero to avoid disturbing sleeping monsters while moving near them.

Description

While a hero has stealth, monsters that are generated asleep will not be awakened with the default ¹⁄₇ chance on each of the hero's moves if that hero is in the monster's direct line of sight, their position is within a 10-square radius of the monster, and the monster is not imitating furniture or an object (e.g. they are a cloaked mimic). This also includes awakening monsters when stepping into special rooms, as well as disturbing other monsters that are easier or harder to awaken—attacking a sleeping monster or creating noise by other means will awaken them as normal, and a sleeping ettin will ignore the effects of stealth ⁹⁄₁₀ of the time.

Sources

The stealth property has multiple sources, both intrinsic and extrinsic. Intrinsic theft can remove a hero's stealth.

Extrinsic stealth

Extrinsic stealth can be granted by several items:

• Elven boots (randomized appearance)
• Elven cloak (faded pall)
• Ring of stealth (randomized appearance)
• The Heart of Ahriman (artifact luckstone)

A hero wearing or putting on armor or rings that grant stealth, or else removing or taking off those items, while they have no other source of the property active will auto-identify them.

Intrinsic stealth

Intrinsic stealth can be granted by several methods:

• Certain roles either start with stealth or gain them at particular experience levels.
  • Archeologists, Rogues and Valkyries start each game with stealth.
  • Monks gain stealth by reaching experience level 5.
  • Rangers gain stealth by reaching experience level 7.
  • Barbarians and Samurai gain stealth by reaching experience level 15.
• A hero eating a ring of stealth has a ¹⁄₃ chance of gainin intrinsic stealth.
• Successfully praying to the hero's god while on a co-aligned altar and being granted intrinsic stealth as a favor. ("I grant thee the gift of Stealth.")

Strategy

Stealth is particularly useful in several of the monster-filled special rooms such as throne rooms and Sokoban's zoo, allowing you to pick off the occupants one by one. Be wary of utilizing stealth in barracks; some higher level soldiers and other occupants may be generated with a bugle, allowing them to wake up the entire room.

Messages

You move very quietly.

You obtained stealth from picking up or carrying on one of the above items.

You sure are noisy.

You did not have another source of stealth and took off an item that granted stealth.

You feel stealthy!

You gained intrinsic stealth, e.g. by leveling up.

You feel clumsy!

You lost intrinsic stealth, e.g. it was stolen by a gremlin.

Variants

SLASH'EM

In SLASH'EM, Whisperfeet is an artifact pair of speed boots that provide stealth when worn.

NetHack Fourk

In NetHack Fourk, there are degrees of stealthiness. Stealth is increased by:

• being an elf, a sylph, or a gnome
• wearing an elven cloak; wearing elven boots
• wearing a +1 or better ring of steath
• having basic or better skill in stealth
• using sufficiently light equipment that you would still be unburdened even if its weight were doubled.

However, being burdened or worse hurts your stealth. Being more stealthy decreases the odds that sleeping monsters will wake up when you walk around. The numerical details for this stealth skill are available in this commit.

xNetHack

In xNetHack, melee combat wakes up nearby monsters, making stealth far less powerful when dealing with monster-filled rooms.

The Big Stick is an artifact club that grants stealth when carried.

EvilHack

In EvilHack, a giant hero cannot start with stealth or gain stealth from any source, except through eating a ring of stealth or successful prayer to their god: sources of the property will auto-identify as normal and print different messages for giants compared to other races of hero.