Flaming sphere

e flaming sphere
Difficulty	9
Attacks	Explode 4d6 fire

e flaming sphere
Difficulty	9
Attacks	Explode 4d6 fire
Base level	6
Base experience	91
Speed	13
Base AC	4
Base MR	0
Alignment	0 (neutral)
Frequency (by normal means)	2 (Quite rare)
Genocidable	Yes
Weight	10
Nutritional value	10
Size	Small
Resistances	fire resistance
Resistances conveyed	fire resistance
A flaming sphere: can fly. does not need to breathe. has no limbs. has no head. is mindless. does not eat. (*) is neither male nor female. is normally generated hostile. can be seen through infravision. never leaves a corpse. gives out light.
Reference	NetHack 3.6.7 - src/monst.c, line 322

A flaming sphere, e, is a type of monster that appears in NetHack. The flaming sphere is a fiery sphere monster that emits light in a 1-square radius around itself, and can burn through webs while moving.

A flaming sphere has a fire explosion attack that causes them to self-destruct and blast a single target for 4-24 base damage, which can cure sliming, has a dexterity-based chance of dealing reduced damage, and is completely blocked by fire resistance. Flaming spheres possess fire resistance.

The spellbook of flame sphere is a deferred item that teaches a spell the hero can use to create tame flaming spheres.

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, flaming spheres create 3x3 explosions with their attacks that can affect items and other monsters caught within the blast radius: this can burn armor and destroy scrolls, spellbooks, potions, and globs of green slime, but does not affect the inventory of a hero that is polymorphed into a flaming sphere and explodes using this attack. This is adapted from xNetHack. The flaming sphere's difficulty rating is also raised to 9, with difficulty calculations adjusted via commit c3802343 to fix related discrepancies.

Per commit eb22a810, item destruction caused by fire damage is dependent on the amount of damage dealt, with the amount of items in open inventory that are affected being equal to ¹⁄₅ of the fire damage inflicted.

Per commit 0eadf8df and commit b25961fb, pets and other monsters can gain intrinsics from killing monsters using digestion attacks, allowing a monster to gain fire resistance by digesting a flaming sphere. Per commit c78e7af0, this also applies to a hero polymorphed into a monster with a digesting attack.

Generation

Randomly generated flaming spheres are always created hostile.

A flaming sphere does not leave a corpse upon death.

Strategy

Flaming spheres are fairly annoying to deal with, though thankfully their explosion attack cannot destroy any of the hero's inventory or burn their armor. Additionally, pets that attack flaming spheres will likely take the explosion in your stead, and fire resistance completely trivializes them. Flaming spheres can also be made to miss if you are invisible or have displacement, and their nonexistent MR score means they can easily be dropped by poison—they can also be put to sleep or otherwise immobilized, allowing a hero or pet to kill them before they explode.

Be sure to keep flaming spheres away from leprechaun halls, treasure zoos and similar rooms that you do not want awakened if possible, and if a zoo contains a flaming sphere, try to save it for last—stealth is valuable for both purposes.

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 9942b65d, extrinsic fire resistance protects the target's open inventory from damage by a flaming sphere explosion ⁹⁹⁄₁₀₀ of the time, with a separate roll for each item that would be destroyed.

History

The flaming sphere first appears in NetHack-- 3.0.10, and also appears in NetHack-- 3.1.3 and SLASH 6. It makes its vanilla debut in NetHack 3.3.0.

From NetHack 3.3.0 to NetHack 3.4.2, including some variants based on those versions, flaming spheres are not properly accounted for in some checks of fiery monsters, and polymorph into a flaming sphere does not cure sliming. These are fixed in NetHack 3.4.3 via commit 5ba58b72 and commit 929f9ce2 so that polymorph into a flaming sphere cures sliming and the monster is accounted for using a macro rather than separate lists.

From NetHack 3.3.0 to NetHack 3.4.3, flaming and shocking spheres are capable of picking up items where a freezing sphere cannot, though due to their weight they will only attempt to pick up very light ones such as singular gold pieces (usually only while tame). This is fixed in NetHack 3.6.0 via commit cbab68a4 so that spheres will properly not attempt to pick up items.

Variants

SLASH'EM

SLASH'EM makes the spellbook of flame sphere and its spell functional: casting the spell summons a tame flaming sphere with 1 HP, and casting it at Skilled or higher in matter spells can summon multiple spheres. These flaming spheres will only exist temporarily, and monsters hit by their explosions are treated as though the hero had attacked them, e.g. awarding them experience for monsters that the sphere kills, angering peaceful monsters and so on. The spell also respects extinction, meaning it has a finite number of uses throughout a given game.

Flaming spheres and heroes polymorphed into flaming spheres take damage when subjected to water, such as from a rust trap or the thrown potion, and are similarly affected by the thrown or wielded potion of amnesia.

All of the above information also applies to SlashTHEM.

dNetHack

In dNetHack, notdNetHack and notnotdNetHack, flaming spheres have an on-death explosion similar to gas spores, covering a 3x3 area centered on it that can burn items in the open inventories of anyone caught in the blast—fire resistance blocks HP damage from the explosion, and extrinsic fire resistance also prevents item damage.

Flaming spheres can be warded by the Elder Elemental Eye at any level of reinforcement.

Flaming spheres may be generated in the Lawful Quest, where they will appear on the Paths of Law and within the Arcadian Tower if Oona's elemental affinity is fire. The summon sphere monster spell can summon flaming spheres.

Flaming spheres (including heroes polymorphed into flaming spheres) take damage when subjected to water, such as from the thrown potion, and are similarly affected by the potion of amnesia or potion of starlight if they are thrown or wielded.

xNetHack

In xNetHack, the explosion attack of flaming spheres covers a 3x3 radius, affecting monsters, armor and items caught in the explosion as well as items in the open inventory of the victims—extrinsic fire resistance protects a hero or monster's open inventory from this damage ⁹⁹⁄₁₀₀ of the time.

SpliceHack

In SpliceHack, the spellbook of flame sphere is made functional and works similar to SLASH'EM.

Reading a scroll of elementalism while confused has a ¹⁄₄ chance of summoning flaming spheres, which are tame if the scroll was blessed and read by a hero and will otherwise be hostile.

All of the above information also applies to Hack'EM.

EvilHack

In EvilHack, the spellbook of flame sphere is made functional and works similar to SLASH'EM, and spheres created by the spell are not counted towards the charisma-based limit for pets.

Flaming spheres use explosion attacks and on-death explosions that cover a 3x3 radius centered on its square, burning monsters, armor and items caught in the explosion—armor that is burnt enough can also be destroyed.

Two flaming spheres are generated in the lava-filled room on the ground floor of the Wizard's Tower during level creation.

Encyclopedia entry

See the encyclopedia entry for sphere.