Stealth

Stealth is an intrinsic ability that appears in Nethack. Sleeping monsters will not be awakened if a player with stealth approaches them.

Specifically, stealth turns off the code that wakes up most monsters when you approach within a 10-square radius. It also turns off the code that wakes up 1/3 of all monsters on the level when you first step into certain special rooms.

Sources

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 (luckstone)

Save for the Heart of Ahriman, if you do not have the stealth intrinsic, then wearing the above items will auto-identify them, as will taking them off.

Intrinsic stealth

Characters can gain intrinsic stealth by:

• Reaching a certain level for some roles
  • Valkyries: 1
  • Rogues: 1
  • Archeologists: 1
  • Monks: 5
  • Rangers: 7
  • Barbarians: 15
  • Samurai: 15
• Eating a ring of stealth
• Being granted a favor while praying to your god on an aligned altar. ("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

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

xNetHack

In xNetHack, melee combat wakes up nearby monsters, making stealth far less powerful when dealing with monster-filled rooms. The new Caveman quest artifact, Big Stick, confers stealth when carried.

Fourk

In 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.