Difference between revisions of "Engine bug"

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m (in some circumstances, positive offsets are ignored as well)
m (Bugs present in Doom II version 1.9 for DOS: default sort alphabetically)
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A [[Doom]] '''engine bug''' is a limitation or an oddity present in the [[Doom engine]]. For errors in [[Levels|map]] design, even those related to a specific item below, see the article about that map.
 
A [[Doom]] '''engine bug''' is a limitation or an oddity present in the [[Doom engine]]. For errors in [[Levels|map]] design, even those related to a specific item below, see the article about that map.
 +
 +
This article uses the version 1.9 [[DOOM2.EXE]] DOS version as the base version. Older versions, the source release, Final Doom and The Ultimate Doom have some minor changes, tweaks and different bugs.
  
 
Note that playing with a [[source port]] may, while removing some or even the majority of the bugs listed below, introduce other bugs which are not listed here (although details may be present in the article about the source port in question).
 
Note that playing with a [[source port]] may, while removing some or even the majority of the bugs listed below, introduce other bugs which are not listed here (although details may be present in the article about the source port in question).
Line 7: Line 9:
 
This table classifies anomalies in a very broad way; see the individual articles for details.
 
This table classifies anomalies in a very broad way; see the individual articles for details.
  
* '''[[Wikipedia:Canon (fiction)|Canonicity]]''' — A bug is ''verified'' only when a current or former [[id Software]] programmer has called it a bug in a public medium.  An unverified bug may still be ''undisputed'' if it is generally accepted as an error or issue by the fan community under a consensus involving thorough playtesting and research on the corresponding phenomenon and any associated [[Wikipedia:Executable file|binaries]] or [[Doom source code|source code]]. A bug is ''disputed'' if it can be argued to be a harmless and possibly intentional feature.
+
* '''{{wp|Canon (fiction)|Canonicity}}''' — A bug is ''verified'' only when a current or former [[id Software]] programmer has called it a bug in a public medium.  An unverified bug may still be ''undisputed'' if it is generally accepted as an error or issue by the fan community under a consensus involving thorough playtesting and research on the corresponding phenomenon and any associated [[Executable file|binaries]] or [[Doom source code|source code]]. A bug is ''disputed'' if it can be argued to be a harmless and possibly intentional feature.
  
 
* '''Cause''' — The general category of underlying problem:
 
* '''Cause''' — The general category of underlying problem:
Line 13: Line 15:
 
*** A few of these arise from simple ''typos'' in the source code.
 
*** A few of these arise from simple ''typos'' in the source code.
 
** Improperly constructed ''[[linedef]]s'' (with orphaned [[tag]]s or incorrectly placed [[texture]]s) or ''[[sector]]s'', can also induce various strange behaviors.
 
** Improperly constructed ''[[linedef]]s'' (with orphaned [[tag]]s or incorrectly placed [[texture]]s) or ''[[sector]]s'', can also induce various strange behaviors.
** The Doom engine includes few safeguards against [[Wikipedia:Arithmetic overflow|''overflow'' conditions]].
+
** The Doom engine includes few safeguards against {{wp|Integer overflow|''overflow'' conditions}}.
** Line-of-sight calculations, [[Doom rendering engine|rendering]] algorithms, and the [[Doom rendering engine#Node building|BSP tree]] are also susceptible to [[Wikipedia:Floating point#Accuracy problems|''roundoff'' errors]].
+
** Line-of-sight calculations, [[Doom rendering engine|rendering]] algorithms, and the [[Doom rendering engine#Node building|BSP tree]] are also susceptible to {{wp|Floating point#Accuracy problems|''roundoff'' errors}}.
 
** The engine imposes a number of ''[[static limits]]'' on [[Thing]] placement and map construction, which sometimes fix one problem by creating another.
 
** The engine imposes a number of ''[[static limits]]'' on [[Thing]] placement and map construction, which sometimes fix one problem by creating another.
  
 
* '''Fatal''' bugs are those where the engine crashes (often with the [[Venetian blind crash|Venetian blind]] effect) or else exits the game in a controlled fashion, usually with an [[error message]].  '''Y*''' means that termination is possible, but not inevitable.  '''N*''' means that the program keeps running, but that rendering or character behavior may be sufficiently compromised that meaningful gameplay becomes impossible.
 
* '''Fatal''' bugs are those where the engine crashes (often with the [[Venetian blind crash|Venetian blind]] effect) or else exits the game in a controlled fashion, usually with an [[error message]].  '''Y*''' means that termination is possible, but not inevitable.  '''N*''' means that the program keeps running, but that rendering or character behavior may be sufficiently compromised that meaningful gameplay becomes impossible.
 
* '''Fixed in 1.9''' — Some bugs appear only in [[versions]] of Doom prior to [[Doom 1.9|v1.9]].
 
  
 
* A bug has a '''workaround''' if it can be avoided by ''reasonable'' compromises in map design, such as when matching every linedef tag to at least one [[sector]], but not when removing [[Invulnerability|invulnerabilities]] from every level containing a sky texture, or also by convenient precautions and other measures taken by the program user, such as when increasing the mouse sensitivity through the configuration file directly, instead of using the menu. '''S''' means that the bug can be avoided only by making one's map smaller or less complex.
 
* A bug has a '''workaround''' if it can be avoided by ''reasonable'' compromises in map design, such as when matching every linedef tag to at least one [[sector]], but not when removing [[Invulnerability|invulnerabilities]] from every level containing a sky texture, or also by convenient precautions and other measures taken by the program user, such as when increasing the mouse sensitivity through the configuration file directly, instead of using the menu. '''S''' means that the bug can be avoided only by making one's map smaller or less complex.
  
 
* A bug is a '''loophole''' if it can be abused to the player's advantage (especially during [[speedrun]]s or [[deathmatch]]es).
 
* A bug is a '''loophole''' if it can be abused to the player's advantage (especially during [[speedrun]]s or [[deathmatch]]es).
 +
 +
=== Bugs present in Doom II version 1.9 for DOS ===
  
 
{| {{prettySortable}}
 
{| {{prettySortable}}
Line 30: Line 32:
 
!Cause
 
!Cause
 
!Fatal?
 
!Fatal?
!Fixed in<br>1.9?
 
 
!Workaround?
 
!Workaround?
 
!Loophole?
 
!Loophole?
Line 37: Line 38:
 
| Undisputed
 
| Undisputed
 
| Algorithm
 
| Algorithm
! N
 
 
! N
 
! N
 
! N
 
! N
Line 45: Line 45:
 
|  
 
|  
 
| Algorithm
 
| Algorithm
! N
 
 
! N
 
! N
 
! N
 
! N
Line 54: Line 53:
 
| Algorithm
 
| Algorithm
 
! Y*
 
! Y*
! N
 
 
! N
 
! N
 
! N
 
! N
Line 61: Line 59:
 
| Undisputed
 
| Undisputed
 
| Algorithm
 
| Algorithm
! N
 
 
! N
 
! N
 
! N
 
! N
Line 70: Line 67:
 
| Overflow
 
| Overflow
 
! N*
 
! N*
! N
 
 
! N
 
! N
 
! N
 
! N
Line 77: Line 73:
 
|  
 
|  
 
| Algorithm
 
| Algorithm
! N
 
 
! N
 
! N
 
! N
 
! N
Line 87: Line 82:
 
! N
 
! N
 
! N
 
! N
! N
 
! N
 
|-
 
| [[Armor percentage rollover]]
 
| Undisputed
 
| Static&nbsp;limit
 
! N*
 
! Y
 
! S
 
 
! N
 
! N
 
|-
 
|-
Line 101: Line 87:
 
|  
 
|  
 
| Algorithm
 
| Algorithm
! N
 
 
! N
 
! N
 
! N
 
! N
Line 112: Line 97:
 
! N
 
! N
 
! N
 
! N
! N
 
|-
 
| [[Barrel suicide]]
 
| Undisputed
 
| Algorithm
 
! N
 
! Y
 
! N
 
! Y
 
 
|-
 
|-
 
| [[Blast damage has unlimited vertical range]]
 
| [[Blast damage has unlimited vertical range]]
 
| Undisputed
 
| Undisputed
 
| Algorithm
 
| Algorithm
! N
 
 
! N
 
! N
 
! N
 
! N
Line 134: Line 109:
 
| Overflow
 
| Overflow
 
! N
 
! N
! N
+
! S
! N
 
 
! N
 
! N
 
|-
 
|-
| [[Broadcast packet meltdown]]
+
| [[Boss level ending not triggered if every player is dead]]
| Verified
+
| Undisputed
|  
+
| Algorithm
 
! N*
 
! N*
! Y
+
! N
!
 
 
! N
 
! N
 
|-
 
|-
Line 149: Line 122:
 
|  
 
|  
 
| Algorithm
 
| Algorithm
! N
 
 
! N
 
! N
 
! N
 
! N
Line 159: Line 131:
 
! N
 
! N
 
! N
 
! N
 +
! N
 +
|-
 +
| [[Chainsaw negates projectile impact thrust]]
 +
| Undisputed
 +
| Algorithm
 
! N
 
! N
 
! N
 
! N
 +
! Y*
 
|-
 
|-
| [[Colormap blink ignores concurrent powerup]] [http://www.doomworld.com/vb/showthread.php?s=&postid=1019768#post1019768]
+
| [[Colormap blink ignores concurrent powerup]] {{dwforumsp|id=1019768|title=}}
 
|  
 
|  
 
|  
 
|  
! N
 
 
! N
 
! N
 
! N
 
! N
 
! N
 
! N
 
|-
 
|-
| [[Barrel#Notes|Crushed barrels leave behind a pool of blood]]
+
| [[Crash when accessing Read This!]] {{dwforums|id=73271|title=}}
 
| Undisputed
 
| Undisputed
| Algorithm
+
|
! N
+
! Y
 
! N
 
! N
! Y
 
 
! N
 
! N
 
|-
 
|-
| [[Crushed monsters block player movement]]
+
| [[Barrel#Notes|Crushed barrels leave behind a pool of blood]]
| Verified
+
| Undisputed
 
| Algorithm
 
| Algorithm
 
! N
 
! N
 
! Y
 
! Y
! N
 
 
! N
 
! N
 
|-
 
|-
Line 189: Line 164:
 
| Undisputed
 
| Undisputed
 
| Algorithm
 
| Algorithm
! N
 
 
! N
 
! N
 
! N
 
! N
Line 197: Line 171:
 
| Undisputed
 
| Undisputed
 
| Algorithm
 
| Algorithm
! N
 
 
! N
 
! N
 
! N
 
! N
Line 206: Line 179:
 
| Algorithm
 
| Algorithm
 
! Y*
 
! Y*
! N
 
 
!  
 
!  
 
! Y
 
! Y
 +
|-
 +
| [[Doom II monster exclusion bug]]
 +
| Undisputed
 +
| Algorithm
 +
! Y*
 +
! Y
 +
! N
 
|-
 
|-
 
| [[Seg#Drawsegs overflow|Drawsegs overflow]]
 
| [[Seg#Drawsegs overflow|Drawsegs overflow]]
 
| Undisputed
 
| Undisputed
 
| Static&nbsp;limit
 
| Static&nbsp;limit
! N
 
 
! N
 
! N
 
! S
 
! S
Line 221: Line 199:
 
| Undisputed
 
| Undisputed
 
| Roundoff
 
| Roundoff
! N
 
 
! N
 
! N
 
! N
 
! N
Line 229: Line 206:
 
| Undisputed
 
| Undisputed
 
| Algorithm
 
| Algorithm
! N
 
 
! N
 
! N
 
! N
 
! N
Line 237: Line 213:
 
| Disputed
 
| Disputed
 
| Algorithm
 
| Algorithm
! N
 
 
! N
 
! N
 
! N
 
! N
Line 245: Line 220:
 
| Undisputed
 
| Undisputed
 
| Algorithm
 
| Algorithm
! N
 
 
! N
 
! N
 
! N
 
! N
Line 253: Line 227:
 
|  
 
|  
 
| Algorithm
 
| Algorithm
! N
 
 
! N
 
! N
 
! N
 
! N
Line 261: Line 234:
 
| Undisputed
 
| Undisputed
 
| Algorithm
 
| Algorithm
! N
 
 
! N
 
! N
 
! N
 
! N
Line 269: Line 241:
 
| Undisputed
 
| Undisputed
 
|  
 
|  
! N
 
 
! N
 
! N
 
! N
 
! N
Line 277: Line 248:
 
|  
 
|  
 
| Overflow
 
| Overflow
! N
 
 
! N
 
! N
 
! N
 
! N
Line 285: Line 255:
 
| Undisputed
 
| Undisputed
 
| Algorithm
 
| Algorithm
! N
 
 
! N
 
! N
 
! N
 
! N
Line 296: Line 265:
 
! N
 
! N
 
! N
 
! N
 +
|-
 +
| [[GUS instrument mappings bug]]
 +
| Undisputed
 +
| Algorithm
 +
! N
 +
! Y
 
! N
 
! N
 
|-
 
|-
Line 301: Line 276:
 
| Undisputed
 
| Undisputed
 
| Algorithm
 
| Algorithm
! N
 
 
! N
 
! N
 
! S
 
! S
Line 309: Line 283:
 
| Undisputed
 
| Undisputed
 
| Linedef
 
| Linedef
! N
 
! N
 
! Y
 
! N
 
|-
 
| [[Health limited to 199]]
 
|
 
| Algorithm
 
 
! N
 
! N
 
! Y
 
! Y
! N
 
 
! N
 
! N
 
|-
 
|-
Line 325: Line 290:
 
|  
 
|  
 
| Algorithm
 
| Algorithm
! N
 
 
! N
 
! N
 
! N
 
! N
Line 334: Line 298:
 
| Algorithm
 
| Algorithm
 
! N
 
! N
!
 
 
!  
 
!  
 
!  
 
!  
Line 341: Line 304:
 
|  
 
|  
 
| Typo
 
| Typo
! N
 
 
! N
 
! N
 
! N
 
! N
Line 349: Line 311:
 
|  
 
|  
 
|  
 
|  
! N
 
 
! N
 
! N
 
! N
 
! N
Line 358: Line 319:
 
| Algorithm
 
| Algorithm
 
! Y
 
! Y
! N
 
 
! N
 
! N
 
! N
 
! N
Line 365: Line 325:
 
| Undisputed
 
| Undisputed
 
| Algorithm
 
| Algorithm
! N
 
 
! N
 
! N
 
! N
 
! N
Line 373: Line 332:
 
| Disputed
 
| Disputed
 
| Algorithm
 
| Algorithm
! N
 
 
! N
 
! N
 
! N
 
! N
 
! N
 
! N
 
|-
 
|-
| [[IRQ 2 does not work]]
+
| [[Configuration file#Additional settings|joyb_speed magic numbers]]
| Verified
 
 
|  
 
|  
!  
+
| Overflow
 +
! N
 +
! Y
 
! Y
 
! Y
!
 
!
 
 
|-
 
|-
| [[Items respawn with pickup flag off]]
+
| [[Key pickup resets palette]]
| Verified
+
| Undisputed
 
| Algorithm
 
| Algorithm
 
! N
 
! N
! Y
 
!
 
!
 
|-
 
| [[Configuration file#Additional settings|joyb_speed magic numbers]]
 
|
 
| Overflow
 
 
! N
 
! N
!  
+
! N
! Y
 
! Y
 
 
|-
 
|-
 
| [[Kill percentage flag used for -nomonsters and respawning]]
 
| [[Kill percentage flag used for -nomonsters and respawning]]
Line 406: Line 354:
 
| Algorithm
 
| Algorithm
 
! N*
 
! N*
! N
 
 
! N
 
! N
 
! Y
 
! Y
Line 414: Line 361:
 
|  
 
|  
 
! Y
 
! Y
! N
 
 
! Y
 
! Y
 
! N
 
! N
Line 421: Line 367:
 
| Undisputed
 
| Undisputed
 
| Algorithm
 
| Algorithm
! N
 
 
! N
 
! N
 
! N
 
! N
Line 429: Line 374:
 
| Undisputed
 
| Undisputed
 
| Roundoff
 
| Roundoff
! N
 
 
! N
 
! N
 
! S
 
! S
Line 437: Line 381:
 
| Undisputed
 
| Undisputed
 
| Typo
 
| Typo
! N
 
 
! N
 
! N
 
! N
 
! N
Line 445: Line 388:
 
| Disputed
 
| Disputed
 
| Algorithm
 
| Algorithm
! N
 
 
! N
 
! N
 
! N
 
! N
Line 454: Line 396:
 
| Algorithm
 
| Algorithm
 
! N
 
! N
! Y
 
 
! N
 
! N
 
! N
 
! N
Line 461: Line 402:
 
| Undisputed
 
| Undisputed
 
| Algorithm
 
| Algorithm
! N
 
 
! N
 
! N
 
! N
 
! N
Line 469: Line 409:
 
| Undisputed
 
| Undisputed
 
| Static limit
 
| Static limit
! N
 
 
! N
 
! N
 
! N
 
! N
Line 477: Line 416:
 
| Disputed
 
| Disputed
 
| Algorithm
 
| Algorithm
! N
 
 
! N
 
! N
 
! N
 
! N
Line 486: Line 424:
 
| Static limit
 
| Static limit
 
!  
 
!  
! N
 
 
! S
 
! S
 
! N
 
! N
Line 493: Line 430:
 
| Undisputed
 
| Undisputed
 
| Algorithm
 
| Algorithm
! N
 
 
! N
 
! N
 
! N
 
! N
Line 502: Line 438:
 
| Linedef
 
| Linedef
 
! Y*
 
! Y*
! N
 
 
! Y
 
! Y
 
! N
 
! N
Line 510: Line 445:
 
| Static limit
 
| Static limit
 
! Y
 
! Y
! N
 
 
! S
 
! S
 
! N
 
! N
Line 517: Line 451:
 
|  
 
|  
 
| Static limit
 
| Static limit
! N
 
 
! N
 
! N
 
! N
 
! N
Line 526: Line 459:
 
| Algorithm
 
| Algorithm
 
! N*
 
! N*
! N
 
 
! Y
 
! Y
 
! N
 
! N
Line 534: Line 466:
 
| Overflow
 
| Overflow
 
! Y
 
! Y
! N
 
! Y
 
! N
 
|-
 
| [[Moiré error]]
 
| Undisputed
 
| Overflow
 
! N*
 
 
! Y
 
! Y
! S
 
 
! N
 
! N
 
|-
 
|-
Line 552: Line 475:
 
! N
 
! N
 
! N
 
! N
 +
|-
 +
| [[Monsters fleeing]]
 +
| Disputed
 +
| Algorithm
 
! N
 
! N
 +
! N
 +
!
 
|-
 
|-
| [[Monsters fleeing]]
+
| [[Monsters may target players without ever seeing or hearing them]]
 
| Disputed
 
| Disputed
 
| Algorithm
 
| Algorithm
Line 560: Line 489:
 
! N
 
! N
 
! N
 
! N
!
 
 
|-
 
|-
 
| [[Monsters open locked doors]]
 
| [[Monsters open locked doors]]
 
| Undisputed
 
| Undisputed
 
| Roundoff
 
| Roundoff
! N
 
 
! N
 
! N
 
! N
 
! N
Line 573: Line 500:
 
| Undisputed
 
| Undisputed
 
| Algorithm
 
| Algorithm
! N
 
 
! N
 
! N
 
! N
 
! N
Line 582: Line 508:
 
| Linedef
 
| Linedef
 
! Y
 
! Y
! N
 
 
! S
 
! S
 
! N
 
! N
Line 591: Line 516:
 
! N
 
! N
 
! N
 
! N
! N
 
! N
 
|-
 
| [[Vertical offsets are ignored in texture patches]]
 
| Undisputed
 
| Algorithm
 
! N
 
! N
 
! N
 
! N
 
|-
 
| [[Network game crashes with 3 or 4 players]]
 
| Verified
 
|
 
! Y
 
! Y
 
!
 
! N
 
|-
 
| [[Network play locks up when using a sound card]]
 
| Verified
 
|
 
! Y
 
! Y
 
!
 
 
! N
 
! N
 
|-
 
|-
Line 621: Line 521:
 
| Undisputed
 
| Undisputed
 
| Overflow
 
| Overflow
! N
 
 
! N
 
! N
 
! N
 
! N
Line 629: Line 528:
 
| Disputed
 
| Disputed
 
| Algorithm
 
| Algorithm
! N
 
 
! N
 
! N
 
! N
 
! N
Line 638: Line 536:
 
| Overflow
 
| Overflow
 
! Y*
 
! Y*
! N
 
 
! S
 
! S
 
! N
 
! N
 
|-
 
|-
 
| [[Ouch face]]
 
| [[Ouch face]]
| Verified [http://rome.ro/smf/index.php/topic,1514.msg31763.html#msg31763]
+
| Verified [https://web.archive.org/web/20100920220554/http://rome.ro/smf/index.php/topic,1514.msg31763.html#msg31763]
 
| Typo
 
| Typo
! N
 
 
! N
 
! N
 
! N
 
! N
Line 653: Line 549:
 
|  
 
|  
 
|  
 
|  
! N
 
 
! N
 
! N
 
! N
 
! N
Line 661: Line 556:
 
|  
 
|  
 
| Algorithm
 
| Algorithm
! N
 
 
! N
 
! N
 
! N
 
! N
Line 669: Line 563:
 
| Disputed
 
| Disputed
 
| Algorithm
 
| Algorithm
! N
 
 
! N
 
! N
 
! N
 
! N
Line 677: Line 570:
 
| Undisputed  
 
| Undisputed  
 
| Algorithm
 
| Algorithm
! N
 
 
! N
 
! N
 
! N
 
! N
Line 685: Line 577:
 
| Disputed
 
| Disputed
 
| Algorithm
 
| Algorithm
! N
 
 
! N
 
! N
 
!  
 
!  
Line 693: Line 584:
 
| Undisputed
 
| Undisputed
 
| Typo
 
| Typo
! N
 
 
! N
 
! N
 
! N
 
! N
Line 702: Line 592:
 
| Overflow
 
| Overflow
 
! N*
 
! N*
! N
 
 
! Y
 
! Y
 
! N
 
! N
Line 709: Line 598:
 
| Disputed
 
| Disputed
 
| Algorithm
 
| Algorithm
! N
 
 
! N
 
! N
 
! N
 
! N
Line 718: Line 606:
 
|  
 
|  
 
! Y
 
! Y
! N
 
 
! Y
 
! Y
 
! N
 
! N
Line 726: Line 613:
 
| Algorithm
 
| Algorithm
 
! N*
 
! N*
! N
 
 
! N
 
! N
 
! N
 
! N
Line 736: Line 622:
 
! N
 
! N
 
! N
 
! N
! N
 
|-
 
| [[Projectiles triggering linedefs]]
 
| Verified
 
| Algorithm
 
! N
 
! Y
 
! N
 
! Y
 
|-
 
| [[PS/2 mouse bug]]
 
| Verified
 
|
 
!
 
! Y
 
!
 
!
 
 
|-
 
|-
 
| [[PWAD size limit]]
 
| [[PWAD size limit]]
Line 758: Line 627:
 
| Algorithm
 
| Algorithm
 
!Y
 
!Y
!N
 
 
!Y
 
!Y
 
!N
 
!N
Line 765: Line 633:
 
| Disputed
 
| Disputed
 
| Algorithm
 
| Algorithm
!N
 
 
!N
 
!N
 
!N
 
!N
Line 773: Line 640:
 
| Disputed
 
| Disputed
 
| Sector
 
| Sector
!N
 
 
!N
 
!N
 
!Y
 
!Y
Line 781: Line 647:
 
|  
 
|  
 
|  
 
|  
!N
 
 
!N
 
!N
 
!N
 
!N
Line 789: Line 654:
 
| Disputed
 
| Disputed
 
| Algorithm
 
| Algorithm
! N
 
 
! N
 
! N
 
! N
 
! N
Line 797: Line 661:
 
| Undisputed
 
| Undisputed
 
| Algorithm
 
| Algorithm
! N
 
 
! N
 
! N
 
! S
 
! S
 
! Y
 
! Y
|-
 
| [[Retriggering an open door after loading a savegame causes crash]]
 
| Verified
 
| Algorithm
 
! Y
 
! Y
 
! N
 
! N
 
 
|-
 
|-
 
| [[Revenant tracers desync internal demos]]
 
| [[Revenant tracers desync internal demos]]
Line 814: Line 669:
 
| Algorithm
 
| Algorithm
 
! N*
 
! N*
! N
 
 
! N
 
! N
 
! N
 
! N
Line 821: Line 675:
 
| Disputed
 
| Disputed
 
| Algorithm
 
| Algorithm
! N
 
 
! N
 
! N
 
! N
 
! N
Line 830: Line 683:
 
| Static limit
 
| Static limit
 
! Y
 
! Y
! N
 
 
! S
 
! S
! N
 
|-
 
| [[Savegame slots 5 and 6 corrupt other files]]
 
| Verified
 
|
 
! N
 
! Y
 
!
 
 
! N
 
! N
 
|-
 
|-
Line 845: Line 689:
 
|  
 
|  
 
| Algorithm
 
| Algorithm
! N
 
 
! N
 
! N
 
! N
 
! N
Line 853: Line 696:
 
|  
 
|  
 
| Algorithm
 
| Algorithm
! N
 
 
! N
 
! N
 
! Y
 
! Y
Line 861: Line 703:
 
|  
 
|  
 
| Algorithm
 
| Algorithm
! N
 
 
! N
 
! N
 
! S
 
! S
Line 872: Line 713:
 
! N
 
! N
 
! N
 
! N
 +
|-
 +
|[[Shotgun sprite wraps vertically in Final Doom]]
 +
|
 +
| Algorithm
 +
! N
 +
! Y
 
! N
 
! N
 
|-
 
|-
Line 877: Line 724:
 
| Undisputed
 
| Undisputed
 
| Static limit
 
| Static limit
! N
 
 
! N
 
! N
 
! N
 
! N
Line 886: Line 732:
 
| Algorithm
 
| Algorithm
 
! N*
 
! N*
! N
 
! N
 
! Y
 
|-
 
| [[Skill level cannot be selected in some network games]]
 
| Verified
 
|
 
 
! N
 
! N
 
! Y
 
! Y
!
 
!
 
 
|-
 
|-
 
| [[Sky hack absorbs attacks regardless of height]]
 
| [[Sky hack absorbs attacks regardless of height]]
 
| Undisputed
 
| Undisputed
 
| Algorithm
 
| Algorithm
! N
 
 
! N
 
! N
 
! N
 
! N
Line 909: Line 745:
 
| Undisputed
 
| Undisputed
 
| Algorithm
 
| Algorithm
! N
 
 
! N
 
! N
 
! N
 
! N
Line 917: Line 752:
 
| Undisputed
 
| Undisputed
 
| Typo
 
| Typo
! N
 
 
! N
 
! N
 
! N
 
! N
Line 927: Line 761:
 
! N
 
! N
 
! N
 
! N
 +
! N
 +
|-
 +
| [[Some Doom 2-specific projectiles triggering linedefs]]
 +
| Verified
 +
| Algorithm
 
! N
 
! N
 
! N
 
! N
 +
! Y
 
|-
 
|-
 
| [[Some game options not preserved in saved games]]
 
| [[Some game options not preserved in saved games]]
 
| Undisputed
 
| Undisputed
 
| Algorithm
 
| Algorithm
! N
 
 
! N
 
! N
 
! N
 
! N
Line 941: Line 780:
 
| Disputed
 
| Disputed
 
| Static limit
 
| Static limit
! N
 
 
! N
 
! N
 
! N
 
! N
Line 949: Line 787:
 
| Disputed
 
| Disputed
 
| Algorithm
 
| Algorithm
! N
 
 
! N
 
! N
 
! N
 
! N
Line 958: Line 795:
 
|  
 
|  
 
! N
 
! N
!
 
 
! N
 
! N
 
!  
 
!  
 
|-
 
|-
| [[Spawn fog in wrong location]]
+
| [[Spawn cubes miss east & west targets]]
 
| Undisputed
 
| Undisputed
| Typo
+
| Algorithm
! N
 
! N
 
 
! N
 
! N
 +
! Y
 
! N
 
! N
 
|-
 
|-
| [[Spawn cubes miss east & west targets]]
+
| [[Spawn fog in wrong location]]
 
| Undisputed
 
| Undisputed
| Algorithm
+
| Typo
 
! N
 
! N
 
! N
 
! N
! Y
 
 
! N
 
! N
 
|-
 
|-
Line 982: Line 816:
 
| Algorithm
 
| Algorithm
 
! Y*
 
! Y*
! N
 
 
! N
 
! N
 
! Y
 
! Y
Line 990: Line 823:
 
| Static limit
 
| Static limit
 
! Y
 
! Y
! N
 
 
! S
 
! S
 
! N
 
! N
Line 997: Line 829:
 
| Undisputed
 
| Undisputed
 
| Algorithm
 
| Algorithm
! N
 
 
! N
 
! N
 
! N
 
! N
Line 1,005: Line 836:
 
| Disputed
 
| Disputed
 
| Algorithm
 
| Algorithm
! N
 
 
! N
 
! N
 
! N
 
! N
Line 1,013: Line 843:
 
|  
 
|  
 
| Algorithm
 
| Algorithm
! N
 
 
! N
 
! N
 
! N
 
! N
Line 1,022: Line 851:
 
| Algorithm
 
| Algorithm
 
! Y*
 
! Y*
! N
 
 
! N
 
! N
 
! N
 
! N
Line 1,029: Line 857:
 
| Disputed
 
| Disputed
 
| Algorithm
 
| Algorithm
! N
 
 
! N
 
! N
 
! Y
 
! Y
Line 1,037: Line 864:
 
| Undisputed
 
| Undisputed
 
|  
 
|  
! N
 
 
! N
 
! N
 
! Y
 
! Y
Line 1,045: Line 871:
 
| Disputed
 
| Disputed
 
| Algorithm
 
| Algorithm
! N
 
 
! N
 
! N
 
! N
 
! N
Line 1,054: Line 879:
 
| Algorithm
 
| Algorithm
 
! N
 
! N
! N
 
! N
 
! Y
 
|-
 
| [[Switches and lifts deactivated when restoring a saved game]]
 
| Verified
 
| Algorithm
 
 
! N
 
! N
 
! Y
 
! Y
! N
 
! N
 
 
|-
 
|-
| [[Tag 666#Bugs|Tag 666 idiosyncrasies]]
+
| [[Tag 666#Difference in behaviour between Doom1 and Ultimate Doom|Tag 666 idiosyncrasies]]
 
| Undisputed
 
| Undisputed
 
| Algorithm
 
| Algorithm
! N
 
 
! N
 
! N
 
! Y
 
! Y
Line 1,078: Line 893:
 
| Algorithm
 
| Algorithm
 
! N*
 
! N*
! N
 
 
! N
 
! N
 
! N
 
! N
Line 1,085: Line 899:
 
| Undisputed
 
| Undisputed
 
| Algorithm
 
| Algorithm
! N
 
 
! N
 
! N
 
! N
 
! N
Line 1,093: Line 906:
 
| Undisputed
 
| Undisputed
 
| Static&nbsp;limit
 
| Static&nbsp;limit
! N
 
 
! N
 
! N
 
! N
 
! N
Line 1,101: Line 913:
 
| Undisputed
 
| Undisputed
 
| Linedef
 
| Linedef
! N
 
 
! N
 
! N
 
! Y
 
! Y
 
! N
 
! N
 
|-
 
|-
| [[Unused frames and obstacle sprite]] [http://www.doomworld.com/vb/post/225726]
+
| [[Unused frames and obstacle sprite]] {{dwforumsp|id=225726|title=}}
 
|  
 
|  
 
|  
 
|  
! N
 
 
! N
 
! N
 
! Y
 
! Y
Line 1,118: Line 928:
 
| Multiple
 
| Multiple
 
! Y
 
! Y
! N
 
 
! N
 
! N
 
! N
 
! N
Line 1,126: Line 935:
 
| Static limit
 
| Static limit
 
! N
 
! N
 +
! N
 +
! N
 +
|-
 +
| [[Vertical offsets are ignored in texture patches]]
 +
| Undisputed
 +
| Algorithm
 
! N
 
! N
 
! N
 
! N
Line 1,133: Line 948:
 
| Undisputed
 
| Undisputed
 
| Static&nbsp;limit
 
| Static&nbsp;limit
! N
 
 
! N
 
! N
 
! S
 
! S
Line 1,142: Line 956:
 
| Static&nbsp;limit
 
| Static&nbsp;limit
 
! Y
 
! Y
! N
 
 
! S
 
! S
 
! N
 
! N
Line 1,150: Line 963:
 
| Algorithm
 
| Algorithm
 
! N*
 
! N*
! N
 
 
! Y
 
! Y
 
! N
 
! N
Line 1,156: Line 968:
 
| [[Wallrunning]]
 
| [[Wallrunning]]
 
| Undisputed
 
| Undisputed
 +
| Algorithm
 +
! N
 +
! N
 +
! Y
 +
|-
 +
| [[Weapon pickup message not displayed in multiplayer]]
 +
|
 
| Algorithm
 
| Algorithm
 
! N
 
! N
 
! N
 
! N
 
! N
 
! N
! Y
 
 
|-
 
|-
 
| [[Weapon sighting is off center]]
 
| [[Weapon sighting is off center]]
 
|  
 
|  
 
|  
 
|  
! N
 
 
! N
 
! N
 
! N
 
! N
Line 1,174: Line 991:
 
|  
 
|  
 
! N
 
! N
 +
! N
 +
! N
 +
|-
 +
| [[Wrong sound origin for button "popouts"]]
 +
| Undisputed
 +
| Algorithm
 
! N
 
! N
 
! N
 
! N
 
! N
 
! N
 
|-
 
|-
| [[Wrong sound origin for button "popouts"]]
+
| [[Wrong sound origin for switch/button presses]]
 
| Undisputed
 
| Undisputed
 
| Algorithm
 
| Algorithm
Line 1,184: Line 1,007:
 
! N
 
! N
 
! N
 
! N
 +
|-
 +
| [[Z_Malloc error]]
 +
| Verified
 +
| Algorithm
 +
! Y
 +
!
 +
! N
 +
|-
 +
|}
 +
 +
=== Bugs present in versions prior to Doom II version 1.9 for DOS ===
 +
{| {{prettySortable}}
 +
!Phenomenon
 +
!Canonicity
 +
!Cause
 +
!Fatal?
 +
!Fixed in<br> version
 +
!Workaround?
 +
!Loophole?
 +
|-
 +
| [[Armor percentage rollover]]
 +
| Undisputed
 +
| Static&nbsp;limit
 +
! N*
 +
! 1.25?
 +
! S
 
! N
 
! N
 
|-
 
|-
| [[Wrong sound origin for switch/button presses]]
+
| [[Barrel suicide]]
 
| Undisputed
 
| Undisputed
 
| Algorithm
 
| Algorithm
 
! N
 
! N
 +
! 1.5?
 +
! N
 +
! Y
 +
|-
 +
| [[Broadcast packet meltdown]]
 +
| Verified
 +
|
 +
! N*
 +
! 1.2
 +
!
 +
! N
 +
|-
 +
| [[Crushed monsters block player movement]]
 +
| Verified
 +
| Algorithm
 +
! N
 +
!
 +
! N
 +
! N
 +
|-
 +
| [[Health limited to 199]]
 +
|
 +
| Algorithm
 +
! N
 +
! 1.25?
 +
! N
 +
! N
 +
|-
 +
| [[IRQ 2 does not work]]
 +
| Verified
 +
|
 +
!
 +
! 1.2
 +
!
 +
!
 +
|-
 +
| [[Items respawn with pickup flag off]]
 +
| Verified
 +
| Algorithm
 +
! N
 +
!
 +
!
 +
!
 +
|-
 +
| [[Moiré error]]
 +
| Undisputed
 +
| Overflow
 +
! N*
 +
! 1.4
 +
! S
 +
! N
 +
|-
 +
| [[Network game crashes with 3 or 4 players]]
 +
| Verified
 +
|
 +
! Y
 +
!
 +
!
 +
! N
 +
|-
 +
| [[Network play locks up when using a sound card]]
 +
| Verified
 +
|
 +
! Y
 +
! 1.2
 +
!
 
! N
 
! N
 +
|-
 +
| [[Projectiles present in The Ultimate Doom triggering linedefs]]
 +
| Verified
 +
| Algorithm
 
! N
 
! N
 +
! 1.4
 
! N
 
! N
 +
! Y
 
|-
 
|-
| [[Z_Malloc error]]
+
| [[PS/2 mouse bug]]
 
| Verified
 
| Verified
 
|  
 
|  
 
!  
 
!  
 +
! 1.666
 +
!
 +
!
 +
|-
 +
| [[Retriggering an open door after loading a savegame causes crash]]
 +
| Verified
 +
| Algorithm
 
! Y
 
! Y
 +
! 1.2
 +
! N
 +
! N
 +
|-
 +
| [[Savegame slots 5 and 6 corrupt other files]]
 +
| Verified
 +
|
 +
! N
 +
! 1.2
 +
!
 +
! N
 +
|-
 +
| [[Skill level cannot be selected in some network games]]
 +
| Verified
 +
|
 +
! N
 +
!
 +
!
 
!  
 
!  
 +
|-
 +
| [[Switches and lifts deactivated when restoring a saved game]]
 +
| Verified
 +
| Algorithm
 +
! N
 
!  
 
!  
 +
! N
 +
! N
 
|-
 
|-
 
|}
 
|}
Line 1,209: Line 1,162:
 
* [[Doom source code oddities]]
 
* [[Doom source code oddities]]
 
* [[Static limits]]
 
* [[Static limits]]
 +
* [[Engine bugs in Heretic]]
 +
* [[Engine bugs in Hexen]]
 +
* [[Engine bugs in Strife]]
  
 
[[Category:Errors and bugs|*]]
 
[[Category:Errors and bugs|*]]
 
[[Category:Doom engine]]
 
[[Category:Doom engine]]
 
[[Category:Lists]]
 
[[Category:Lists]]

Revision as of 16:38, 2 May 2022

A Doom engine bug is a limitation or an oddity present in the Doom engine. For errors in map design, even those related to a specific item below, see the article about that map.

This article uses the version 1.9 DOOM2.EXE DOS version as the base version. Older versions, the source release, Final Doom and The Ultimate Doom have some minor changes, tweaks and different bugs.

Note that playing with a source port may, while removing some or even the majority of the bugs listed below, introduce other bugs which are not listed here (although details may be present in the article about the source port in question).

Key

This table classifies anomalies in a very broad way; see the individual articles for details.

  • Canonicity — A bug is verified only when a current or former id Software programmer has called it a bug in a public medium. An unverified bug may still be undisputed if it is generally accepted as an error or issue by the fan community under a consensus involving thorough playtesting and research on the corresponding phenomenon and any associated binaries or source code. A bug is disputed if it can be argued to be a harmless and possibly intentional feature.
  • Cause — The general category of underlying problem:
    • Most bugs are due to algorithms which fail to account for all possible inputs, apply conditional statements in an illogical sequence, or have unforeseen consequences in particular game situations.
      • A few of these arise from simple typos in the source code.
    • Improperly constructed linedefs (with orphaned tags or incorrectly placed textures) or sectors, can also induce various strange behaviors.
    • The Doom engine includes few safeguards against overflow conditions.
    • Line-of-sight calculations, rendering algorithms, and the BSP tree are also susceptible to roundoff errors.
    • The engine imposes a number of static limits on Thing placement and map construction, which sometimes fix one problem by creating another.
  • Fatal bugs are those where the engine crashes (often with the Venetian blind effect) or else exits the game in a controlled fashion, usually with an error message. Y* means that termination is possible, but not inevitable. N* means that the program keeps running, but that rendering or character behavior may be sufficiently compromised that meaningful gameplay becomes impossible.
  • A bug has a workaround if it can be avoided by reasonable compromises in map design, such as when matching every linedef tag to at least one sector, but not when removing invulnerabilities from every level containing a sky texture, or also by convenient precautions and other measures taken by the program user, such as when increasing the mouse sensitivity through the configuration file directly, instead of using the menu. S means that the bug can be avoided only by making one's map smaller or less complex.
  • A bug is a loophole if it can be abused to the player's advantage (especially during speedruns or deathmatches).

Bugs present in Doom II version 1.9 for DOS

Phenomenon Canonicity Cause Fatal? Workaround? Loophole?
(0,0) respawning bug Undisputed Algorithm N N Y
1% damage bug Algorithm N N N
Absurd texture name in error message Undisputed Algorithm Y* N N
AASTINKY and AASHITTY Undisputed Algorithm N N N
All-ghosts effect Undisputed Overflow N* N N
Anomalous angry face behavior Algorithm N N N
Arch-Vile fire spawned at the wrong location Undisputed Typo N N N
Baron attacks a monster behind him Algorithm N N N
Barrel explosions which do no damage Undisputed Algorithm N N N
Blast damage has unlimited vertical range Undisputed Algorithm N N Y
Blockmap overflow Undisputed Overflow N S N
Boss level ending not triggered if every player is dead Undisputed Algorithm N* N N
Bullet puffs do not appear in outdoor areas Algorithm N N
Chaingun makes two sounds firing single bullet Undisputed Algorithm N N N
Chainsaw negates projectile impact thrust Undisputed Algorithm N N Y*
Colormap blink ignores concurrent powerup [1] N N N
Crash when accessing Read This! [2] Undisputed Y N N
Crushed barrels leave behind a pool of blood Undisputed Algorithm N Y N
Demo desyncing caused by bouncing lost souls Undisputed Algorithm N N N
Demo desyncing caused by menu access Undisputed Algorithm N N N
Demon speed bug Algorithm Y* Y
Doom II monster exclusion bug Undisputed Algorithm Y* Y N
Drawsegs overflow Undisputed Static limit N S N
Elastic collisions with walls Undisputed Roundoff N N Y
Fast doors make two closing sounds Undisputed Algorithm N N N
Fast doors reopening with wrong sound Disputed Algorithm N N N
Final Doom teleporters do not set Z coordinate Undisputed Algorithm N N N
Firing frame position not updated when the player dies Algorithm N N N
Flawed collision detection Undisputed Algorithm N N
Floors and ceilings moving silently Undisputed N N Y
Frag count rollover Overflow N N N
Gamma correction resets palette Undisputed Algorithm N N Y
Ghost monsters Undisputed Algorithm N N N
GUS instrument mappings bug Undisputed Algorithm N Y N
Hall of Mirrors effect (limit) Undisputed Algorithm N S N
Hall of Mirrors effect (missing texture) Undisputed Linedef N Y N
Health percentage hysteresis in sector type 11 Algorithm N N N
Hitscan attacks hit invisible barriers in large open areas Algorithm N
IDCHOPPERS cheat confers 1 tic of invulnerability Typo N N
IDCLEV idiosyncrasies N N N
IDMUS requests invalid music Algorithm Y N N
Inaccurate trigonometry table Undisputed Algorithm N N N
Invulnerability colormap bug Disputed Algorithm N N N
joyb_speed magic numbers Overflow N Y Y
Key pickup resets palette Undisputed Algorithm N N N
Kill percentage flag used for -nomonsters and respawning Disputed Algorithm N* N Y
Linedef type 37 Y Y N
Linedefs can be activated regardless of player's Z position Undisputed Algorithm N N Y
Long wall error Undisputed Roundoff N S N
Lopsided final boss explosions Undisputed Typo N N N
Lost soul charging backwards Disputed Algorithm N N Y
Lost soul clipping problems Undisputed Algorithm N N N
Lost soul colliding with items Undisputed Algorithm N N Y
Lost soul limit Undisputed Static limit N N Y
Lost soul target amnesia Disputed Algorithm N N N
Lump size limit Static limit S N
Mancubus fireball clipping Undisputed Algorithm N N N
Manual doors on 1S lines cause an illegal operation Undisputed Linedef Y* Y N
Map size limit (blocks) Undisputed Static limit Y S N
Map size limit (integer overflow) Static limit N N N
Medusa effect Undisputed Algorithm N* Y N
Menu error with high mouse sensitivity Undisputed Overflow Y Y N
Monsters attacking across tall ledges Disputed Algorithm N N N
Monsters fleeing Disputed Algorithm N N
Monsters may target players without ever seeing or hearing them Disputed Algorithm N N N
Monsters open locked doors Undisputed Roundoff N N Y
Monsters stuck in doortracks, walls or hanging off lifts Undisputed Algorithm N N Y
Moving platforms limit Undisputed Linedef Y S N
Moving platform heights not preserved in saved games Undisputed Algorithm N N N
Noclip bug Undisputed Overflow N N Y
Non-Newtonian motion of corpses Disputed Algorithm N N Y
Numeric overflow crash in tall areas Undisputed Overflow Y* S N
Ouch face Verified [3] Typo N N N
Par times hidden in Final Doom after idclev or reload N N N
Partial invisibility's fuzz effect stays still Algorithm N N N
Partial invisibility stippling algorithm Disputed Algorithm N N N
Pause bug in menus with scroll bars Undisputed Algorithm N N N
Phantom fireball explosions Disputed Algorithm N N
Picked up a medikit that you REALLY need! Undisputed Typo N N N
Player corpses walking Undisputed Overflow N* Y N
Player face grins after restoring savefile Disputed Algorithm N N N
Player starts missing Undisputed Y Y N
Player stuck on ledge after restoring savefile Undisputed Algorithm N* N N
Projectiles explode on impact with "sky" Algorithm N N N
PWAD size limit Undisputed Algorithm Y Y N
Quantum lost soul Disputed Algorithm N N N
Raising sectors change to orphaned sector type Disputed Sector N Y N
Random sound pitch removed N N N
Ranged attacks blocked by decorations Disputed Algorithm N N Y
Recurrent blast damage Undisputed Algorithm N S Y
Revenant tracers desync internal demos Undisputed Algorithm N* N N
Rocket passes through the player who fired it Disputed Algorithm N N Y
Savegame buffer overflow Undisputed Static limit Y S N
Screen melt effect during Doom II cast sequence Algorithm N N N
Secret exit idiosyncrasies Algorithm N Y N
Secret sectors appear or disappear Algorithm N S N
Sector type 17 is disabled after loading a saved game Undisputed Algorithm N N N
Shotgun sprite wraps vertically in Final Doom Algorithm N Y N
Silent BFG trick Undisputed Static limit N N Y
Single-use line actions can fail Undisputed Algorithm N* N Y
Sky hack absorbs attacks regardless of height Undisputed Algorithm N N N
Sky never changes in Doom II Undisputed Algorithm N N N
Sleeping Sergeant of Doom II MAP02 Undisputed Typo N N
Slime trails Undisputed Roundoff N N N
Some Doom 2-specific projectiles triggering linedefs Verified Algorithm N N Y
Some game options not preserved in saved games Undisputed Algorithm N N N
Sound cutoffs Disputed Static limit N N N
Sound effects behave differently on level 8 Disputed Algorithm N N N
Sounds changing pitch on slow computers N N
Spawn cubes miss east & west targets Undisputed Algorithm N Y N
Spawn fog in wrong location Undisputed Typo N N N
Spawn spots not preserved in saved games Undisputed Algorithm Y* N Y
Spechits overflow Undisputed Static limit Y S N
Spider paralysis Undisputed Algorithm N N Y
Sprites flickering across ledges or lifts Disputed Algorithm N N N
Sprites improperly clipped Algorithm N N N
Stairs create unknown sector types Undisputed Algorithm Y* N N
Stairs that can be ascended, but not descended Disputed Algorithm N Y N
Starting on a vertex between visplanes causes illegal memory access Undisputed N Y N
Status bar face hysteresis Disputed Algorithm N N N
Straferunning Undisputed Algorithm N N Y
Tag 666 idiosyncrasies Undisputed Algorithm N Y N
Tag 667 idiosyncrasies Undisputed Algorithm N* N N
Targets not preserved in saved games Undisputed Algorithm N N Y
Turning resolution is lowered when recording demos Undisputed Static limit N N N
Tutti-frutti effect Undisputed Linedef N Y N
Unused frames and obstacle sprite [4] N Y N
Venetian blind crash Undisputed Multiple Y N N
Vertical cutoff of partially invisible sprites Undisputed Static limit N N N
Vertical offsets are ignored in texture patches Undisputed Algorithm N N N
Visible sprites limit Undisputed Static limit N S N
Visplane overflow Undisputed Static limit Y S N
Voodoo doll Undisputed Algorithm N* Y N
Wallrunning Undisputed Algorithm N N Y
Weapon pickup message not displayed in multiplayer Algorithm N N N
Weapon sighting is off center N N N
Wrong sound for exit switches N N N
Wrong sound origin for button "popouts" Undisputed Algorithm N N N
Wrong sound origin for switch/button presses Undisputed Algorithm N N N
Z_Malloc error Verified Algorithm Y N

Bugs present in versions prior to Doom II version 1.9 for DOS

Phenomenon Canonicity Cause Fatal? Fixed in
version
Workaround? Loophole?
Armor percentage rollover Undisputed Static limit N* 1.25? S N
Barrel suicide Undisputed Algorithm N 1.5? N Y
Broadcast packet meltdown Verified N* 1.2 N
Crushed monsters block player movement Verified Algorithm N N N
Health limited to 199 Algorithm N 1.25? N N
IRQ 2 does not work Verified 1.2
Items respawn with pickup flag off Verified Algorithm N
Moiré error Undisputed Overflow N* 1.4 S N
Network game crashes with 3 or 4 players Verified Y N
Network play locks up when using a sound card Verified Y 1.2 N
Projectiles present in The Ultimate Doom triggering linedefs Verified Algorithm N 1.4 N Y
PS/2 mouse bug Verified 1.666
Retriggering an open door after loading a savegame causes crash Verified Algorithm Y 1.2 N N
Savegame slots 5 and 6 corrupt other files Verified N 1.2 N
Skill level cannot be selected in some network games Verified N
Switches and lifts deactivated when restoring a saved game Verified Algorithm N N N

See also