Explosion

In NetHack, an explosion can result from the use (or misuse) of certain items as well as the effects of certain traps.

Description

Explosions can occur through various methods, and will generally take one of three forms:

• Large explosions cover a 3x3 range of squares and damage heroes or monsters caught in the area, sometimes affecting items on those squares as well. Damage from these explosions is dealt to other monsters first, with the hero saved for last.
• 'Directed' explosions will target a specific square and affect any hero or monster on that square.
• Some forms of item destruction will cause affected items to 'explode', which can deal additional damage on top of any caused by whatever destroyed the items and does not usually involve one of the other explosion types.

Some monster attack types involve explosions:

• An explosion attack uses a directed explosion of the given damage type targeted at the square of a hero or monster, killing the attacker in the process regardless of if the attack hits.
• An on-death explosion passively causes a 3x3 explosion of the given damage type if the monster that has it dies from HP loss (including death rays and deadly poison), and that explosion will be centered on the dying monster's square.

The following information pertains to an upcoming version (NetHack 3.7.0). If this version is now released, please verify that the information below is still accurate, then update the page to incorporate it.

Per commit 6b60618e, the explosion attacks of spheres use "real" 3x3 explosions of their respective elements, damaging heroes and monsters caught within the explosion range and affecting their open inventory as well as the squares themselves and any items on them (e.g. freezing spheres cooling lava and turning moats to ice, or flaming spheres melting ice and burning scrolls and books).

Explosions by damage type

Explosions can use the various damage types listed below.

Magical explosion

A "magical explosion" can encompass varying types of explosions:

• The exploding effect of a magic trap, which destroys it and damages whoever stepped on the trap to activate that effect—a hero that is not killed by the explosion will also have their current and maximum power increased.
• The result of a bag of holding exploding when the hero inserts a wand of cancellation, bag of tricks, another bag of holding, or a small-enough container holding any of these items inside that bag of holding.

Depending on the specific type, the explosion will do physical damage (and thus be subject to half physical damage) or magical damage that is affected by magic resistance and half spell damage.

Noxious explosion

The noxious explosion is used by the on-death explosion of a gas spore: despite its name, the 3x3 explosion that it creates deals normal physical damage to any hero or monster caught in the blast.

Fiery explosion

A fiery explosion deals fire damage, which can be reduced or nullified by fire resistance, and is produced by the following:

• Applying a wand of fire with charges to break it, which creates a 3x3 fireball
• Casting the fireball spell
  • Basic or lower-skill castings create a ray that explodes in a 3x3 fireball upon hitting something
  • Skilled or higher castings cause multiple 3x3 fireballs to explode around a concentrated area
• The unused fireball monster spell, which creates a 3x3 fireball upon hitting a monster or wall like the player spell
• Reading a scroll of fire, which creates a 3x3 fireball on the reader's square that can be targeted on a visible square instead if the scroll was blessed
• Throwing a potion of oil that is lit, or dipping either type of lamp into a potion of oil while either item is lit, both of which causes a 3x3 fireball
• A flaming sphere using its explosion attack, which does not affect items, will burn away sliming and is completely blocked by fire resistance

Fireballs from these explosions that hit multiple squares can burn armor and destroy potions, scrolls and spellbooks in the open inventory of affected monsters, as well as melting ice and burning away sliming.

Frosty explosion

A frosty explosion deals cold damage, which can be reduced or nullified by cold resistance, and is produced by the following:

• Applying a wand of cold with charges to break it, which creates a 3x3 cold explosion
• Casting the cone of cold spell, which creates multiple 3x3 cold explosions around a concentrated area at Skilled or higher castings
• A freezing sphere using its explosion attack, which does not affect items and is completely blocked by cold resistance

Cold blasts from these explosions that hit multiple squares can destroy potions in the open inventory of affected monsters, as well as freezing water and lava.

Shocking explosion

A shocking explosion or lightning explosion deals shock damage, which can be reduced or nullified by shock resistance, and is produced by the following:

• Applying a wand of lightning with charges to break it, which creates a 3x3 lightning explosion
• A shocking sphere using its explosion attack, which does not affect items and is completely blocked by shock resistance

Shocking blasts from these explosions that hit multiple squares can destroy wands and rings. Shocking explosions use the same tiles as magical explosions do.

Deferred types

Some explosion types have tiles assigned to them that are not used to draw any explosions in normal gameplay—these explosion types are 'dark', 'muddy' and 'wet'.