Earthquake
An earthquake is a very rare type of item effect that occurs in NetHack. Earthquakes will often affect most or all of a given dungeon level, and can alter or destroy dungeon features even when they are normally resistant in other cases.
The only item that is capable of causing an earthquake is the drum of earthquake.
Description
An earthquake has several effects on the current dungeon level:
- Several pit traps will occur within the hero's proximity, possibly including on their square—this can occur even on undiggable levels. Moats, pools and lava will flow into pits made in adjacent squares, and boulders on squares where pits are created will immediately fill in those pits and bury any items on the boulder's square (interestingly including other boulders).
- Any hero or monster that is dropped into a pit this way, including a pit whose square they were on without being inside the pit itself, takes the usual falling damage and will suffer instant stoning from any footrice corpses that they were wielding or sharing the pit square with—a hero or monster that is already in a pit will be jostled around violently and suffer damage with the same conditions for instant stoning. This damage is subject to half physical damage, and flight, levitation or clinging to the ceiling will prevent a hero or monster from falling into any pits this way.
- A hero that has a pit opened on their position while they are tethered to a heavy iron ball that is buried on their square will have the iron chain tethering them broken.[1]
- A hero that is trapped in a pit at the time of being subjected to an earthquake has a chance of taking reduced damage and "keeping their footing" that is dependent on their luck, dexterity and whether or not they are an Archeologist, and this chance is much lower if they are currently fumbling[2]—a hero that keeps their footing exercises dexterity, and will not be subjected to stoning from footrice corpses that are in the pit or currently being wielded by them.[3]
- Doors, altars, fountains, sinks, graves and thrones in the affected area will be destroyed, with the exception of high altars in Moloch's Sanctum and on the Astral Plane. Damage incurred to a shop door from an earthquake caused by the hero will anger the shopkeeper.
- All immobile monsters on the dungeon level will regain their mobility, and awaken all sleeping monsters on the level, shake loose monsters that are hiding on the ceiling, and scare any monsters that are within a Euclidean distance of 23.7 squares from the hero's position and fail a check versus their MR score.[4][5]
Additionally, if the hero caused the earthquake (which is always the case for NetHack in practice), the following applies:
- Monsters within a distance of 4*[(XL - 1) / 3 + 1]+1 to the hero that are awakened by the earthquake will become hostile.[6][7]
- Any peaceful monsters that are dropped into a pit due to the earthquake will also become hostile.
- Any monsters that are killed from falling into pits as a result of the earthquake will be attributed to the hero, breaking pacifist conduct and incurring any appropriate penalties (e.g. to alignment record or luck) for peaceful monsters or pets that die this way.
History
The earthquake effect first appears in NetHack 3.0.0 with the drum of earthquake.
Messages
Variants
Some NetHack variants make earthquakes possible through other means besides the drum of earthquake, and may alter how earthquakes affect the dungeon.
UnNetHack
In UnNetHack, harassment from the Wizard of Yendor can cause an earthquake unless it occurs when the hero is on the Elemental Planes.
dNetHack
In dNetHack, notdNetHack and notnotdNetHack, several items and abilities can cause earthquakes to occur:
- The earthquake monster spell will naturally cause an earthquake when cast.
- A hero invoking The Earth Crystal will cause an earthquake to occur.
- A hero invoking The Ruinous Descent of Stars will cause up to 1d4 (1d(level⁄10 + 1)) clusters of fiery explosions and earthquakes at random places on the current dungeon level.
- A hero invoking the Great Claws of Urdlen will cause an earthquake to occur.
- A hero invoking The Silence Glaive and selecting down (>) when prompted for a direction will trigger three earthquakes in sequence after killing all genocide-vulnerable monsters on the level including the hero (which life saving can rescue them from).
- After the hero either kills the Wizard of Yendor or picks up the Amulet of Yendor for the first time, an earthquake will occur the next time they visit a level containing the sepulcher of a dread seraph, and a chasm will open that frees the seraph from its sepulcher.
EvilHack
In EvilHack, harassment from the Wizard of Yendor can cause an earthquake unless it occurs when the hero is on the Elemental Planes, similar to UnNetHack.
Hack'EM
In Hack'EM, dropping or throwing a bomb into a vent has a 3⁄5 chance of destroying the vent and causing a small earthquake.
References
- ↑ src/music.c in NetHack 3.6.7, line 380-L390
- ↑ src/music.c in NetHack 3.6.7, line 406-L424
- ↑ src/music.c in NetHack 3.6.7, line 416-L424
- ↑ src/music.c in NetHack 3.6.7, line 61: awaken_monsters() function
- ↑ src/music.c in NetHack 3.6.7, line 652: calls awaken_monsters() for drum of earthquake
- ↑ src/music.c in NetHack 3.6.7, line 265: call to wakeup() from do_earthquake()
- ↑ src/mon.c in NetHack 3.6.7, line 3027: wakeup() function; the call sets via_attack to TRUE
