Sneak attack (dNetHack)

dNetHack and notdNetHack expand upon the sneak attack mechanic from NetHack. There are several new ways to sneak attack in addition to backstabbing fleeing enemies, along with additional methods to both gain the ability to perform sneak attacks and increase their power. Sneak attacks are also possible with ranged attacks as well as melee attacks, and monsters can perform sneak attacks under the right circumstances.

In order to perform a sneak attack, the attacker must have both some ability that lets them sneak attack (giving them at least one sneak attack dice), and some circumstance that renders the defender vulnerable to a sneak attack (which determines the method of sneak attack).

Sneak attack dice

There are many ways to gain the ability to sneak attack. These each grant +1 sneak attack die, and they all stack:

Dice for general use

• There are some sources that only apply to the player:
  • +1 die for a Rogue while not polymorphed
  • +1 die for a Drow Anachrononaut (Myrkalfar) while not polymorphed
  • +1 die with Andromalius bound to the player
• +1 die if the attacker is a sneaky, backstabbing type of monster (or the player polymorphed into one)

Dice for specific weapons

• There are some sources that only apply to the player:
  • +1 die for a Convict attacking with a wielded spoon while not polymorphed
  • +1 die when making a melee attack with a lit lightsaber using the Juyo form
  • +1 die for a Healer attacking with a wielded knife while not polymorphed
• +1 die when attacking with the wielded Spineseeker
  • +1 bonus die if the sneak attack is from behind (see below), for a total of +2 dice
• +1 die when attacking with a wielded bestial claw while the beast's embrace glyph is active
• +1 die when attacking with the wielded Pen of the Void that has Andromalius bound into it
  • +1 bonus die if the Pen is in its dual-bladed form (post-quest), for a total of +2 dice

The following information pertains to an upcoming version (dNetHack). If this version is now released, please verify that it is still accurate, then update the page to incorporate this information.

In 3.23.0, attackers will get +1 die when attacking with the wielded Lolth's Fang, and another +1 bonus die if the defender is trapped in a web, for a total of +2 dice.

The Pen of the Void with Andromalius inside will gain sneak attack dice when used to attack even while not wielded (e.g. when thrown).

A user has suggested improving this page or section as follows:

"List of MG_BACKSTAB monsters?"

Sneak attack conditions

In order to for the attacker to sneak attack, the defender must have anatomy, the attacker must not be engulfed, and the attacker must not be hitting themself. The attacker must also have a valid method of sneak attacking the defender, exploiting some disadvantage that the defender is at:

• The defender can be attacked while helpless if they are paralyzed, laughing, stunned, confused, or sleeping.
  • If the player is the defender, it also applies to anything that makes the player helpless, or while they're in the middle of a multi-turn action.
• The defender can be attacked while suicidal if they are affected by the Suicidal madness.
• The defender can be attacked while blinded.
  • If the player is the defender, this only applies if the player has no way to see or sense the attacking monster.
• The defender can be attacked while trapped, e.g. in a pit, web, or bear trap
  • If the player is the defender, it also applies when they are held by a monster
• There are a few ways to attack from behind (also known as a backstab):
  • the player attacks a monster, and the monster is looking for the player in totally the wrong direction (both wrong about whether the player is north/in-line/south of them, and wrong about whether the player is west/in-line/east of them)
  • the player attacks a monster, and the monster has no idea where the player is (e.g. if the monster hasn't noticed the player yet)
  • the defender is a monster, and they are fleeing
  • the defender is the player, and they can't see or sense the attacking monster
• If the player attacks a monster, and the monster doesn't know exactly where the player is, then the player can attack while hidden and catch the monster flat-footed in a couple of cases:
  • the player is more than 8 moves away from the monster, i.e. they snipe the monster
  • the player is attacking with The Lifehunt Scythe wielded in their main hand, and the monster has a head and is alive or undead (not e.g. a golem)

Juyo is trained by making melee attacks with a lit lightsaber in Shii-Cho or Juyo form, as long as the target is disadvantaged (i.e. if the attacker has a sneak attack method, even if they have no sneak attack dice). Currently this is bugged and Juyo will always be trained in Juyo form, even if the target is not disadvantaged.

The following information pertains to an upcoming version (dNetHack). If this version is now released, please verify that it is still accurate, then update the page to incorporate this information.

In 3.23.0, Juyo training is fixed to require the target to be disadvantaged.

Sneak attacks are usually announced by combat messages, but only when the player is the attacker.

Sneak attack damage and bonuses

If the attacker has at least one sneak attack dice and a valid method of sneak attack, and this attack is not a multihit, then they will make a sneak attack. They roll the sneak attack dice and add them to their attack's damage. The size of the sneak attack dice is normally equal to the attacker's level (a monster's current monster level, your experience level if not polymorphed, or your polymorph form's base monster level), capped at 30 (the maximum player level). e.g. if the attacker is level 30 and has 2 sneak attack dice, then the sneak attack will add +2d30 damage.

If the attack was made with the weapon Silver Starlight, or if the attacker is a Cuprilach Rilmani, then the sneak attack die size is increased by 50%. These two bonuses do not stack.

There are some thoughts (from glyphs) that will trigger when the player makes a sneak attack:

• The clawmark glyph increases sneak attack die size by 30%
• The rapturous eye glyph heals 30 HP
• The writhe glyph restores 30 energy

Melee sneak attacks with The Lifehunt Scythe have a ¹⁄₂₀ chance of beheading the target. This requires that the attack target have a head.

If the player makes a melee sneak attack with a lit lightsaber using Juyo, they have a chance for a staggering blow, and they always get movement points refunded. See the Juyo page for more details. These staggering blows are intended to trigger at 60% lower odds when not sneak attacking, but currently they are bugged and will never trigger when not sneak attacking.

The following information pertains to an upcoming version (dNetHack). If this version is now released, please verify that it is still accurate, then update the page to incorporate this information.

In 3.23.0, Juyo can correctly trigger staggering blows when not sneak attacking.

The clawmark glyph now increases total damage of sneak attacks by 30%, not just the sneak attack dice.

A user has suggested improving this page or section as follows:

"Any notdNetHack-exclusive sneak attack sources/effects? Strategy section?"