Bug Hall of Fame - Revision history

DoktorL: Add the one that I myself encountered

2025-12-30T12:13:52Z

Add the one that I myself encountered

Umbire the Phantom: /* SLASH'EM */ pothole

2023-11-22T18:00:59Z

‎SLASH'EM: pothole

K2: /* Vanilla NetHack */ 3.7.0 hall of fame bug

2023-01-19T17:04:24Z

‎Vanilla NetHack: 3.7.0 hall of fame bug

Tomsod: my two cents

2021-11-16T16:10:46Z

my two cents

FIQ at 22:53, 15 June 2021

2021-06-15T22:53:20Z

Actual-nh: Grammar/style

2021-01-02T23:46:44Z

Grammar/style

FIQ: potential invocation skip as result of previous bug, no idea if you could pull it off though

2021-01-02T23:27:22Z

potential invocation skip as result of previous bug, no idea if you could pull it off though

FIQ: fiqhack: dungeon branch generation overwriting other branches

2021-01-02T23:25:11Z

fiqhack: dungeon branch generation overwriting other branches

ScienceBall: Punctuation

2020-12-07T05:28:16Z

Punctuation

Stenno: "Vorpal exploit" was the only bold entry in the list - it's now displayed normally

2019-10-07T17:46:35Z

"Vorpal exploit" was the only bold entry in the list - it's now displayed normally

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 * In one version, the [[vibrating square]] did not generate, but [[Moloch's Sanctum]] could be reached via a simple [[level teleport]] without  meeting any of the normal requirements, allowing an alternative method of completing the game.
 * Pets who knew "cancellation" would cast it repeatedly at the player, making it impossible for the player to maintain intrinsic protection, and eventually ruining their inventory.
 == Other ==

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 == SLASH'EM ==
-* It's possible to enchant a weapon to +127 by [[polypile|polymorphing]] it into a [[dwarvish mattock]], [[upgrade|upgrading]] it to a [[pick-axe]], further polymorphing it into a [[tinning kit]] or an [[expensive camera]], [[charging]] that tool until it has 127 charges, and then waiting for it to revert.  A +127 [[long sword]] can then be turned into [[Excalibur]], while a +127 [[bow]] or other [[launcher]] can fire 40 or more projectiles at once.
+* It's possible to enchant a weapon to +127 by [[polypile|polymorphing]] it into a [[dwarvish mattock]], [[upgrading]] it to a [[pick-axe]], further polymorphing it into a [[tinning kit]] or an [[expensive camera]], [[charging]] that tool until it has 127 charges, and then waiting for it to revert.  A +127 [[long sword]] can then be turned into [[Excalibur]], while a +127 [[bow]] or other [[launcher]] can fire 40 or more projectiles at once.
 * [[Pit#Buried objects|Burying]] a [[medical kit]] and then waiting for it to rot leaves behind the pills it contained, which can then be consumed for a chance of a [[wish]].  An average medical kit contains about 10 pills, while the wish chance is {{frac|1|7}}, so it's possible to farm wishes by repeatedly wishing for medical kits.

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 * Amulet delivery service: In Nethack 3.4.3, covetous monsters (for example, [[Asmodeus]]) would teleport to the High Priest of Moloch in [[Moloch's Sanctum]], fight and kill them, pick up the Amulet of Yendor, and then teleport back to you. Players would bring a strong covetous monster to the sanctum on purpose and let it fetch the amulet for them. This reduced the time spent in Moloch's Sanctum to about 40 turns, without the character ever having to move away from the upstairs and only having to fight a single monster. This was spoiler bug SC343-19.
 * From at least [[3.1.0]] until [[3.6.6]], a monster using [[Stormbringer]]'s [[drain life]] attack on another monster would result in healing the player instead of the attacker.  Many variants inherited this bug.
 == NetHack 4 ==

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 * Time distortion bug: In NetHack 3.4.3, the code handling sinking into lava would treat ''any'' command (even something simple such as checking the inventory) as though it cost time. This was bug C343-231.
 * Amulet delivery service: In Nethack 3.4.3, covetous monsters (for example, [[Asmodeus]]) would teleport to the High Priest of Moloch in [[Moloch's Sanctum]], fight and kill them, pick up the Amulet of Yendor, and then teleport back to you. Players would bring a strong covetous monster to the sanctum on purpose and let it fetch the amulet for them. This reduced the time spent in Moloch's Sanctum to about 40 turns, without the character ever having to move away from the upstairs and only having to fight a single monster. This was spoiler bug SC343-19.
 == NetHack 4 ==
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 == UnNetHack ==
 * The Bell of Opening could fail to generate, making the game unwinnable.
 == SLASH'EM Extended ==

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 * At one time, reading a non-blessed scroll of earth would cause an infinite number of boulders to fall on you.
 * A bug resulting from a reworking of code handling branch connections made it possible to end up in Home:0 by digging down from the Quest goal level. The game ended up reading Mines level data as Quest filler, and unless the player had already generated the Mines, would generate Quest filler in place of it. Continuing upwards to Home:-1 and beyond would, if the player hadn't visited the Mines' top level, eventually overwrite Gehennom data, including the Sanctum, replacing it with Quest filler. If it was possible to skip generating the Sanctum this way and generate what the game considered to be the VS level, as Quest filler, you could then enter Gehennom properly (by branchporting for example) and skip the invocation by going to the VS (replaced with Quest filler) and taking the downstairs there.
 == NetHack Fourk ==

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 * It used to be possible for samurai player monsters on the samurai quest to read scrolls of genocide and instantly kill the player.
 * At one time, reading a non-blessed scroll of earth would cause an infinite number of boulders to fall on you.
-* A bug resulting from a reworking of code handling branch connections made it possible to end up in Home:0 by digging down from the Quest goal level. The game ended up reading Mines level data as Quest filler, and unless the player had already generated the Mines, would generate Quest filler in place of it. Continuing upwards to Home:-1 and beyond would eventually, if the player hadn't visited the Mines top level, eventually overwrite Gehennom data, including the Sanctum, replacing it with Quest filler.
+* A bug resulting from a reworking of code handling branch connections made it possible to end up in Home:0 by digging down from the Quest goal level. The game ended up reading Mines level data as Quest filler, and unless the player had already generated the Mines, would generate Quest filler in place of it. Continuing upwards to Home:-1 and beyond would eventually, if the player hadn't visited the Mines top level, eventually overwrite Gehennom data, including the Sanctum, replacing it with Quest filler. If it was possible to skip generating the Sanctum this way and generate what the game considered to be the VS level, as Quest filler, you could then enter Gehennom properly (by branchporting for example) and skip the invocation by going to the VS (replaced with Quest filler) and take the downstairs there.
 == NetHack Fourk ==

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 == AceHack MP ==
-* AceHacks multiplayer mode would teleport a character to an otherwise inaccessible "waiting room" area above the top Sokoban level on save. When a player restored the game again, the character would be teleported to their old location. Note that this was a literal teleport - if the character was in a shop carrying unpaid items, the shopkeeper would consider it a theft and would be angry when the game was restored.
+* AceHack's multiplayer mode would teleport a character to an otherwise inaccessible "waiting room" area above the top Sokoban level on save. When a player restored the game again, the character would be teleported to their old location. Note that this was a literal teleport - if the character was in a shop carrying unpaid items, the shopkeeper would consider it a theft and would be angry when the game was restored.
 == Splicehack ==

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 == Vanilla NetHack ==
-* '''The Vorpal Exploit:''' The game did not correctly re-roll the d20 it uses when calculating whether a thrown weapon will hit, meaning that the to-hit roll of a thrown weapon would always be the same until the player took some other action to reroll the die (such as making a melee attack). [[Vorpal Blade]] also uses the to-hit roll to decide whether it makes a decapitation attack. Together, this allowed the player to melee with Vorpal Blade until getting a decapitation, after which all attacks made by throwing Vorpal Blade would have a guaranteed decapitation, until the next melee attack. Once discovered, this bug was also found to exist in all NetHack variants, including SLASH'EM. In GruntHack, the bug works the same way with weapons that have the vorpal [[object property]].
+* The Vorpal Exploit: The game did not correctly re-roll the d20 it uses when calculating whether a thrown weapon will hit, meaning that the to-hit roll of a thrown weapon would always be the same until the player took some other action to reroll the die (such as making a melee attack). [[Vorpal Blade]] also uses the to-hit roll to decide whether it makes a decapitation attack. Together, this allowed the player to melee with Vorpal Blade until getting a decapitation, after which all attacks made by throwing Vorpal Blade would have a guaranteed decapitation, until the next melee attack. Once discovered, this bug was also found to exist in all NetHack variants, including SLASH'EM. In GruntHack, the bug works the same way with weapons that have the vorpal [[object property]].
 * NetHack 3.1.0 had a "ludicrous bug" where [[Yeenoghu]]'s confusion attack would fall through due to a missing break statement, causing it to run the code that handles Death's melee attack. This allowed Yeenoghu to instakill players without magic resistance and drain maximum HP with his melee attacks. This bug went unreported for three major versions of the game because of a misplaced source code comment that made it look like intended behavior. It was removed in 3.4.0.
 * Branchport skip: In NetHack 3.4.3, the player could skip most of the ascension run with the Eye of the Aethiopica, because the branchporting code did not care if their mount was carrying the amulet. The character could drop the amulet, then wait until their pet would pick it up, then quickly mount it and invoke branchporting to sokoban or the mines. The pet would drop the amulet again after a few turns.