Doom community jargon

As with any other long-running community, the Doom community has a long list of technical jargon, memes, slang terms, idioms, and catchphrases. Without knowledge of these terms, many Doom community discussions may be indecipherable for new members or new mappers. An example sentence would be as follows:

"The borders in your map have wiggle problems, but you can only see them if you're bottlenecking the stairs. Maybe replace them with slopes or widen that area out? Also, remove the number of hitscanners in those hallways because it's almost impossible on UV MAX unless I spam plasma from the map before. This would be impossible on pistol start."

- Hypothetical advisor

This list is by no means exhaustive, but should help a newbie in understanding the gist of old and new Doom community discussion.

#

 * 1024 - A mapping style inspired by Exquisite Corpse with a simple constraint: The player must never leave a 1024x1024 space in the map. Due to the limitations, advanced mapping tricks are employed to make full use of the level space. 1024 maps were popular in the mid 2000s, and are still being created today. Other variants of 1024 include 2048, 512, and, in joke WAD style, 64.


 * 1 Monster - A mapping style that only allows one monster type per map.


 * 10 Sectors - Originally a Doomworld competition held in 2000, this mapping style only allows 10 sectors. Most 10 sector maps require Boom compatible source ports due to the use of Boom's sector effects. A variant of this style, 2 Sectors, was not as popular as 10 sectors, although many maps in that style were created for ZDoom, which allows the player to walk on top of things. A recent variant in the same vein of 10 Sectors is 100 Lines.

A

 * ACS - A scripting language and corresponding format that originated in Raven Software's Hexen. Often implied to refer to what is actually Extended ACS, an evolution of the ACS language and bytecode format supported by ZDoom and the Eternity Engine.


 * Agitating skeleton - A nickname for the revenant. Originally from a satirical "How-To" YouTube video by Matt Cibulas (RottKing), it was popularized by the 4chan  group.


 * Alignment - More specifically "texture alignment," adjustments made to the vertical and horizontal positioning of textures in Doom levels to provide an aesthetically pleasing appearance.


 * Attacking the ZDoom - The act of designing a mod to push the limits of ZDoom to the point of hilarious errors, or to exploit a bug in a ZDoom feature in order to obtain a desired effect. Originally from a Community is Falling 3 screenshot displaying a bug in the dialogue system, in which the screenshot read, "You will pay for attacking the ZDoom".


 * AV - Short for Alien Vendetta, a popular PWAD for speed running. Could also refer in brief to the arch-vile.

B

 * Ball shit snakes - Ancient Doomworld forums meme from a disgruntled member with a questionable grasp of English.


 * BFG whore - Competitive Doom trash-talk for a player who consistently abuses the BFG9000, especially in areas where avoiding the tracer cone is impossible.


 * Boom - An source port, one of the first to be created, notable for its extended mapping features. Boom lives on in two of the modern source ports: PrBoom+ and the Eternity Engine. Can also refer to Boom compatible.


 * Boom compatible - A map designed to use Boom mapping features or depending on its extended limits. Boom compatible maps usually run in every popular source port, with few exceptions.


 * Borders - Small sectors with a slightly raised floor that outline a main floor along a wall, analogous to moulding in a house. Borders were a mapping fad in the mid-2000s.


 * Botting - Use of an . Due to the simplicity of Doom mechanics, it is easy to spot an active aimbot. Since Doom uses autoaim, use of an aimbot is seen as a form of griefing.


 * Bottlenecking - The act of leading monsters into a small area or opening to make them easier to take out. Some in the scene have viewed this tactic as "cheap" and have designed their maps to discourage bottlenecking or eliminate it entirely.


 * Brightmap - Usually a term for a bitmap containing information for brightened areas of a texture to be lit in-game regardless of lighting conditions, brightmaps retain this definition in hardware source ports. In software-rendered source ports, brightmaps may refer to a specially constructed COLORMAP which has entries that retain full brightness regardless of a sector's light level. Strife is a notable example, where it is applied to robots, computer panels, and texture- and sprite-based lights.


 * Brutal Doom - Gameplay mod for ZDoom. While highly notable and having a large following, many of its gameplay changes, including extreme gore, fatalities, lethal hitscanners, and the ability to insult monsters with a "flip off" keybind, are controversial and divisive within the community. A few believed that Brutal Doom was the of the Doom Community, and left the scene. Derived phrases from this mod include: "Not Brutal enough", "Does this run with Brutal Doom?", and "Brootal."


 * BSP - Binary space partitioning, a method of searching a pre-calculated from the geometry of a map in order to determine the drawing order of walls. Since BSPs are binary trees, the effort required to classify a point in space is reduced to . The use of a BSP tree allows Doom to render large, complex areas with relative ease and little overdraw. May also refer to the first community-created, eponymous node builder, BSP.


 * Bump - To obtain an item by exploiting a flaw in the collision code which allows collection of items through solid walls or across ledges. The most famous bump is the "plasma bump" in Doom II's MAP01: Entryway during deathmatch, where the plasma gun can be picked up by running with speed into the raised platform upon which it sits.

C

 * Caco - Short for cacodemon.


 * Cardboard - An optimized software renderer by Stephen McGranahan (SoM). Used in the Eternity Engine.


 * COLORMAP - A lump in a WAD file that most software renderers use to determine light levels.


 * Compet-n - Derived from "competition;" refers to the "Compet-n database", a website hosting Doom speed runs which were recorded under the site's strict rules.


 * Complevel - Short for "compatibility level", a feature in PrBoom that allows demos recorded from various versions of Boom and Doom to be played back without desyncs. Further shortened to cl in some contexts, such as "run this demo with cl2".


 * Copypasta - A term for the action of a mapper directly copy-pasting sections of a map solely for the sake of breaking up perceived monotony. An example would be a large number of "sector lights" in a hallway that would otherwise be barren. Prudent texture use can help remedy this problem.


 * Corona - A bright ring displayed around light sources in some Doom mods and source ports, usually accomplished with an alpha-blended sprite. This term originated in hardware-accelerated source ports like Doom Legacy. Doomsday uses the term "halo" for this effect. Though not technically correct, "lens flare" may be used interchangeably.


 * Cybie - A cyberdemon.

D

 * Decal - A graphic drawn on a wall in some source ports to show blood splatter or wall damage, such as bullet holes and plasma scorches. Doom Legacy was the first to add this effect, known as "splats." Doom was supposed to ship with a wall damage system, described as "violent bread crumbs" in the initial press release by id Software, but it was never implemented.


 * DECORATE - Content definition language used to create actors and weapons in ZDoom and compatible ports. Comes in two flavors, with the original format largely unsupported. Intended as a temporary stopgap in the never-ending wait for DoomScript, it became an instant hit with Doom modders and is arguably the primary reason for ZDoom's current dominance.


 * DeePsea patches - Tall patches, an extension to Doom's primary column-based image format.


 * DeHackEd - A program designed to allow modifying various aspects of the executable file for Doom, and the distributable patch files created by it (DEH). Most source ports have support for loading DeHackEd patches, making binary modification no longer necessary outside of DOS.


 * DEHSUPP - A lump for ZDoom that defines DeHackEd capabilities; modifying the DEHSUPP lump allows to alter the effects of a DEHACKED patch, including giving access to states and codepointers from other supported games such as Heretic. It has since been deprecated in favour of DECORATE, but is still used and extended in ZDaemon. DEHSUPP was the subject of controversy among some who protested its removal with no suitable replacement ready to fill the gap.


 * Delted - Slang for "deleted." Comes from a joke page touting a site-wide hacking of Doomworld by community member Ralph Vickers (Ralphis).


 * Desync - Short for 'desynchronize', usually used to describe a situation in which demo playback fails due to inconsistencies in the game state. Desyncs may also affect multiplayer games during play, causing the current game to end abruptly.


 * Dime - A Doom speed runner who famously rocket-suicided while streaming. To "pull a Dime" or to be "Dimed" means to rocket suicide by wall or enemy.


 * Dummy sector - A dummy sector is a sector in a map which is usually inaccessible or unseen to the player, but still serves a purpose. Dummy sectors can be used for special effects that otherwise would break. Notable examples are the imp closet in MAP01, using a dummy sector for sound propagation, and the glowing tunnel room hiding the chainsaw secret in E1M2, where a dummy sector is placed against the tunnel wall to power the lighting effect. Many of Boom's new editing features depend on dummy sectors.

E

 * EDF - A content definition language for the Eternity Engine.


 * Eternity Engine - An advanced source port that can render portals. It can also play high-intensity maps such as those found in Sunder with a tolerable framerate.

F

 * Fake contrast - A feature of the Doom engine which allows orthogonal walls to be lit either brighter or dimmer than walls that are non-orthogonal, depending on the walls' direction. Highly visible in square map geometry such as crates. This feature primarily exists to increase contrast. Some source ports allow this to be disabled or "smoothed" across various angles. Hexen is notable for not having it at all.


 * Fake floor - A lowered sector with no lower textures on its surrounding sidedefs, which causes the floor flat to bleed across as if there is no intervening sector. These can be used as traps by hiding monsters into the floor or to create various special effects.


 * FDA - First demo attempt. A "blind run" of a map or set of maps in which the player plays to completion regardless of performance.


 * Flags - Usually a numeric value for source ports which sets binary switches to enable/disable certain features. Common phrases include "dmflags," short for "deathmatch flags", and "compflags," short for "compatibility mode flags." Flags are also present in the original game, used to set options for linedefs, things, and actors.


 * Flat detailing - The use of additional sectors on floors to give a sense of an uneven or damaged floor. Used primarily on hexagon tiles, and was a fad in the mid-2000s.


 * Fog - An earlier method of light diminishing that hardware accelerated source ports used when advanced shading techniques were either unavailable or too GPU-intensive. Can also mean custom color light diminishing in source ports that allow this, such as ZDoom. Hardware fog was canonically added to the Doom engine in the Sony PlayStation version, and used even more extensively in Doom 64.


 * Frad - A deliberate misspelling of "fraud." Popular IRC slang in the late 1990s and early 2000s.


 * FraggleScript - A (mostly deprecated) scripting language for source ports invented by Simon Howard (Fraggle). Was first featured in SMMU, removed from the Eternity Engine, and then added to GZDoom.

G

 * Geezy - A nickname of GZDoom, from a combination of how "GZ" is pronounced in, and the southern hip-hop rapper.


 * Ghost - Monsters with zero width and height, making them able to pass through walls and rendering them immune to most sources of damage. Usually created by an arch-vile resurrecting a crushed monster.


 * git - The "development" version of a source port. The term is from, a revision control system for software. Usually used in sentences like "Use the latest git revision."


 * Glide - A glide is accomplishing the movement of the player through 32-unit gaps via building up a large amount of momentum and bypassing clipping checks against intervening linedefs or by otherwise perfectly fitting through the narrow space. Some glides may be damage assisted, via enemy attacks or rocket explosions. A void glide is a similar phenomenon which causes the player to pass outside the intended bounds of a map. All of these can become sequence break maneuvers and are thus used by speed runners.


 * Gothic - A mapping style inspired by the GothicDM series, a main hallmark of which is intricate detailing. May or may not imply use of the GothicDM texture set as well.


 * Gothic99 - A deathmatch mapset known for its ridiculously detailed first level, and often held up as one of the first instances of "over-detailing." For a few years, most mappers did not want to be associated with "Gothic99" levels of detail, and would state this explicitly. If a map is described as "Gothic99-ish," it is usually not meant as a compliment.

H

 * Heh - Originally an interjection for expression of sorrow or surprise, first attested in the mid-fifteenth century. It eventually morphed into a term for light laughter by the 1800s. It is a dominant form for expression of amusement on IRC, next to the equally popular "lol." Later (mis-)appropriated for use in.


 * Helled - A thread on Doomworld forums was sent to Post Hell with extreme prejudice.


 * Hitscan - Attacks in Doom that are not projectiles - they immediately register a hit on a wall or a thing. A "hitscanner" is a monster that uses hitscan attacks.


 * HMP - Hurt me plenty skill level.


 * HNTR - Hey, not too rough skill level.


 * HOM - Short for "hall of mirrors", a shimmering, mirror-like effect that occurs due to the no-clipping cheat code, missing textures, or malformed nodes. Some source ports have "HOM detection" which blinks colors if any HOM is in the frame. The shimmering is no longer visible in many source ports, due to its dependence on the low-level behavior of video hardware.


 * HR - Short for Hell Revealed. HR2 similarly stands for Hell Revealed 2.


 * Hub - A set of maps that can be visited and revisited in a non-linear order, as seen notably in Hexen and Strife.


 * HUD - Short for heads-up display, a term co-opted from the military by first-person shooter games. May also refer to the status bar or a different display entirely.

I

 * Illusio-pit - A term invented by the author of Wow, named one of the Top 10 Infamous WADs by Doomworld, for the fake floor effect created by missing lower textures around the perimeter of a sunken sector, which causes the flat of the surrounding higher sector to bleed across it. While originally invented in jest, the neologism has found serious use as a term for legitimate uses of this level construct, which predate Wow with initial appearances as a special effect as early as.


 * Instadoom - Gameplay mod for Doom. Its gameplay changes include taking selfies in-game with various filters. Due to its widespread popularity and significant coverage given to it in mainstream and gaming press, a few believed that Instadoom was the of the Doom Community, and left the scene. There seems to be some sort of pattern, here.


 * Impse - A graphic adult fan fiction about a marine, his imp, and a berserk pack. Had a sequel called Mancse which was not as enduring in popularity.


 * ITYTD - I'm too young to die skill level.

J

 * Joke WAD - Any WAD with humorous elements which may or may not impact gameplay. There may or may not be any traditional gameplay contained in them. There are usually a lot of community references in joke WADs, including cameos of various Doom community members. Not to be confused with a Terry WAD.

L

 * Limit removing - Describes a map that runs in source ports which extend static limits.


 * Looks like Christmas - Originally the description of the BFG 2704's plasma fire by John Romero, due to its combination of red and green projectiles. Also referred to by Midway Games map designer Randy Estrella as a lighting scheme to be avoided in Doom 64. It can be used to describe texture choices that complement each other to the point of clashing and being overbearing (e.g., a green wall with a red floor).


 * Longtics - A modified demo format that retains turning precision lost during normal (shorttic) demos.


 * Longwall - Also known as "long wall." Slang for long wall error, a phenomenon in which walls wobble about due to the limited precision of Doom's renderer. Most source ports fix this issue. If you have a long wall in your map, split it up using vertices until you are satisfied. However, beware of a drawsegs overflow.


 * Loser - A term for a Doomworld Forums member that has been put in time out due to his or her misbehavior. Losers cannot post in any forums but the Losers forum, which is only visible otherwise by administrators, moderators, and a handful of Doom community veterans. A member who has been sent to Losers is said to be "losered". Losers may lose their custom forum titles as punishment.


 * Lump - A single asset in a WAD file. Can be a texture, marker, sound, map element, or any other type of data.

M

 * Max - A "maximum" Doom speed run demo. Usually 100% items, kills, and secrets. Example: "UV Max" meaning attainment of a 100/100/100 score in Ultra-Violence skill level.


 * Meatball - A common nickname for the pain elemental, due to its brown, lumpy, round appearance.


 * MM - Short for Memento Mori, a famous PWAD. Popular with speed runners.


 * Monster closet - A small portion of a level that contains one or more enemies and is initially sealed off from the rest of the map, usually serving as a remotely triggered trap. Often used with a negative connotation; this element of gameplay as it appears in Doom and elsewhere is popularly derided for being unimaginative, unrealistic, or immersion-breaking.


 * MUS - DMX music format used by Doom, similar to MIDI.

N

 * Needs more detail - A running gag in the Doom modding community, usually in response to a map that has more detail than needed to convey a sense of place.


 * Nickbakery - Nonsense. Formerly implied an "overreaction to drama," but use in this sense has been lost. Term references Nick Baker (NiGHTMARE).


 * Node - A "leaf" or branching point of a tree - more specifically, a BSP tree. You build "nodes" for Doom levels using a node builder.


 * NM - Nightmare! skill level.

O

 * OPL - A basic Yamaha FM synthesizer for the PC originally invented for the AdLib sound card and later adapted onto the SoundBlaster and compatibles. Some source ports are capable of emulating its unique sound in software.

P

 * Pacifist - A style of play where the player must use no weapons unless required to get to the exit, relying on monster infighting where necessary.


 * Particle - A small rendered object, usually a single colored square, that is used for special effects in source ports. Popularized by the Quake series, particles may be used to simulate fluid-like effects such as blood, water, and projectiles. Particles are usually not regarded as things, but may be created by a spawner thing, such as a particle fountain. Source ports that support particles must be able to render many instances of them for a convincing effect.


 * PC - Short for "partial conversion". A WAD that may contain new maps, sounds, and even sprites, but not to the extent of a total conversion. This may be subjective, however, as WADS like Back to Saturn X may replace nearly every asset but are still Doom themed, and therefore not frequently referred to as partial conversions.


 * Pinky - A demon; the term was popularized by id Software developers due to the monster's coloration. The Doom 3 version of the monster is officially named this despite no longer being pink. The name was also used for a character in the Doom movie who transforms into a similar monster.


 * Pistol start - Playing each level in a set of maps with no weapons or power-ups acquired from the previous levels. Useful for testing custom maps. A required condition for many classes of speed runs.


 * PLAYPAL - The actual color palette for Doom. There are 14 palettes for Doom, including for damage, collection of items, and the green tinge of the radiation suit. If you change the PLAYPAL entries, you can display colors that were not in the original game.


 * Plus - As in "Doom Plus," a binary patch for original Doom engine executables which extends static limits by rearranging variables within the program's data segment in order to enlarge the involved arrays.


 * Portal - A source port feature which enables the player to see into another area in the map that would be either distant or occluded otherwise. These portals can make effects like room-over-room, or -style levels with never-ending hallways.


 * PrBoom+ - Also known as PrBoom-Plus. A source port based on Boom which is popular with speed runners and has the largest range of demo compatibility out of all ports.


 * Purist - Refers to a person or a source port which is dedicated, possibly to the extent of fanaticism, to the purpose of playing Doom in the way that id Software apparently intended. For ports, this means implementing the game while changing nothing unnecessary in the course of porting it to its destination platform. For people, this indicates a rejection of such as mouse look, jumping, and in some cases, even higher resolutions. See also vanilla, for a similar term which lacks the ideological connotations.


 * PWAD - Original id Software terminology. A "patch WAD," traditionally loaded with the -file command. John Romero insisted that this feature be adapted in order to support modding. The system was detailed accordingly by Tom Hall in the Doom Bible and implemented by John Carmack, who liked making his games hackable.

R

 * REJECT - A table used by the Doom engine for fast determination of which sectors can be seen from a given sector. For maps with many monsters, having a REJECT table can speed up the game by disregarding areas that cannot be seen from a monster's position. Creating a very accurate table can take a long time, and as of this writing, there is no perfect REJECT builder. Loses some advantage in modern source ports, where support of large maps causes the REJECT table to become a significant source of cache misses.


 * The Revenant wears pants - A Doomworld Forums meme and humorous reference to the frequent belief by fans of the series that revenants, as they appear in Doom II covered with blood and gore, are wearing red shorts. This belief is sometimes influenced by the Doom novels, whose authors apparently shared this conviction and wrote it into their story as such.


 * Rip and tear - A meme that pays homage to the Doom comic, which contains other one-liner gems such as "Sweet Christmas", "You have huge guts", "Who's a man-and-a-half?", "Here comes the night train!", and "Now I'm radioactive, that can't be good!"


 * Rocket jumping - Use of a rocket to fling the player into an area that would otherwise be inaccessible. Usually performed with walls, as Doom has no concept of vertical aim. Quake players may consider the Doom version of the move laughable, despite its versatility, due to the flashy vertical thrust and low splash-back of explosions in the Quake series of games. It is a proven speed running technique, however.

S

 * Savescumming - Rapidly saving and loading progress while playing a difficult map at any time, or any map for the first time. There has been comical debate on whether or not excessive quick-saving and quick-loading is cheating, but can be seen as annoying during streaming. The term jumped to the Doom community from the western RPG gaming community, where is a common mechanic.


 * Shorttics - A demo in the original format, complete with decreased precision while turning.


 * Slaughtermap - A map focused around challenging gameplay in the form of overwhelming hordes of monsters, most notably mid-tier monsters. Most slaughtermaps are made for Doom 2 due to the larger monster roster.


 * Slime trail - A vertical line of floor or ceiling texture that escapes the boundaries of its intended area, and draws on top of another floor. This is due to the flood-fill-like algorithm for drawing floors and ceilings interacting with inaccurate nodes or limited numeric precision in the Doom engine. Slime trails gained their name from an area of E1M1: Hangar in which a slime texture bled onto a raised concrete floor surrounding it.


 * Slopes - Mapping feature which allows creation of ramps, inclines, and angled architecture. Initially adapted from Ken Silverman's BUILD engine; popularized by ZDoom.


 * Software - A rendering mode for a source port that supports a column-based rendering engine. "Software renderers" closely match the original renderer in Doom, and generally involve no hardware acceleration. Some PWAD text files may stress to the player to play the maps "in software."


 * Source port - A custom version of Doom that runs on various platforms. May include extra features for modding or playing. Term was coined by the original back-port of Linux Doom to DOS, known as DOSDoom. The term expanded to include all source mods, even when no actual porting is taking place, over the objections of some programmers to its technical inaccuracy.


 * Spam - A compressed volley of super shotgun or chaingun fire, plasma rifle shots, rockets, or BFG balls. Usually seen in deathmatch, it can be used to "blind" the opposing player in dark areas. "Spamming" can also be in the form of spreading projectiles by rapidly turning back and forth while firing.


 * Sparklies - A nickname given to the stray pixels that can be seen when a plane meets a wall, or when a platform or floor is sectioned to show more than one flat. Notable examples include the final teleporter in E1M8, and any textured wall with a notable gradient in a sector the height of the texture. Sparklies occur due to lack of precision in the software renderer. Some source ports have special techniques to remedy these issues, but some opt to keep the original behavior due to adherence to the vanilla renderer, or simply for pure speed. A variant of sparklies were known to plague early hardware-accelerated source ports due to a phenomenon known as "t-junctions". This latter form of sparklies is also referred to as "space ants."


 * SR-50 - The fastest form of movement possible in the Doom engine, referring to "strafe run" combined with the speed of the player's motion in units per tic. See also SR-50 automation, for a form sometimes considered to be cheating.


 * STARTAN - The texture name of the iconic walls in E1M1: Hangar of Doom, originally inspired by the padded interior of the Millennium Falcon space ship of the franchise. Since it is a default texture for sidedefs in many map editors, liberal use of STARTAN may be seen as lazy.


 * SVN - The "development" version of a source port. Short for, a revision control system for software. Usually used in sentences like "Use the latest SVN". Use is declining due to the increasing prominence of git for modern revision control.


 * Swingshot - The belief that turning quickly while firing the super shotgun deals greater damage. Sometimes used superstitiously by competitive Doomers in a manner similar to a sporting ritual, this technique's effectiveness was debunked with the release of the Doom source code.

T

 * Telefrag - The act of fragging an opponent or monster by teleporting to his location, resulting in an instant, gory death.


 * Terry WAD - A WAD specifically designed to piss you off, take up space, or do both. While some are simply screamers, others have been more malicious and may attempt to change the player's settings or use up significant disk space and memory.


 * THREE-DEE FUCKING FLOORS - A mockery of maps that used GZDoom's 3D floors to obnoxious ends. This would cause some players' computers to chug along at unplayable frame rates. The situation was compounded by the fact that ZDoom could not render 3D floors during this time, resulting in only a handful of players who had the hardware capable of rendering such maps being able to play them. Usage was mostly confined to the Skulltag forums, which are no longer active.


 * Tic - Short for "tick", a single unit of time in the game logic. For the sake of brevity, Doom logic runs at around 35 tics per second. In vanilla Doom, a frame is displayed to the screen every 35 tics if possible, thus Doom animates at 35 frames per second maximum.


 * Torm - Adding detail to a map to the point of excess. Phrase comes from Tormentor667, who some consider to have a reputation for obsessive detailing to the point of performance loss in game.


 * TC - Total conversion, or a WAD that replaces the majority of the maps, sprites, sounds, and either through DeHackEd or a content definition language, the monsters and objects in Doom. The first famous TC, and the modification which first coined the term, was Aliens TC.


 * Transfer - Effects added as part of the Boom source port's editing features which require the setup of a "dummy" or reference sector or linedef from which properties will be transferred to another tagged structure in the map.


 * Tyson - To complete a map, usually for a speed run demo, with the bare essentials needed to trigger lines and get to the exit. Usually this means restriction to the pistol and fist only, but in certain situations the chainsaw may also be acceptable.

U

 * UV - Ultra-Violence skill level.

V

 * Vanilla - Vanilla Doom. When describing a map, this means the map should run on the original unmodified Doom without problems.


 * Vile - An arch-vile.


 * Visplane - A term from the source code for a data structure used to store and determine regions of the screen to paint as floors or ceilings. If a visplane is not cut off correctly due to imprecision in the renderer or bad nodes, slime trails occur. Notorious for being subject to a strict static limit based on the number of sectors in view with differing properties; a nefarious enemy of early Doom map creators. See also visplane overflow.


 * Visplane overflow - An error in Vanilla Doom in which the game would crash due to exhaustion of available visplanes. This is because was faster than  on slow systems due to the reduction of cache misses (which would be seen as "hitches" during gameplay), and was seen as an acceptable sacrifice. During Doom II's development, the number of visplanes was increased at request of id Software's level designers. Modern source ports remove this limit through various methods.

W

 * Waggle - The term given to undulating floors in Hexen and source ports which borrow the feature from it. ZDoom extended the effect to be able to apply to ceilings as well.


 * Wiggle - The term given to rendering errors on two-sided linedefs caused by the imprecise trigonometric lookup tables and fixed-point math used by the Doom renderer. This is observed in game as a "wiggle" along ledges and ceiling edges when walking alongside them.


 * Wait for DoomScript - A phrase repeated to ZDoom forum users who request a feature that would be difficult to implement using the available tools. DoomScript is a  scripting language for ZDoom which would replace and unify ACS and DECORATE.


 * Wallrunning - The phenomenon of going faster by pushing against an orthogonal wall while moving. Can also be achieved using things, where it may be referred to as "thingrunning."

Y

 * Y-shearing - A technical term for the side-effect of enabling mouselook in software renderers. Mouselook works by moving up or down the of the player. Since software renderers are column-based and will always render walls parallel to the near and far plane of the frustum, this causes a "shearing" distortion effect comparable to the transformation effects of an.


 * You are the demons - A meme popularized in the Doom: Repercussions of Evil fan fiction by Peter Chimaera, in which the protagonist suddenly and unexplainedly turns into a zombie at the end of the tale. The fanfic is notable for its many quotable lines and misspellings, to the point that some Doomers deliberately misspell terms in homage to it.

Z

 * ZDoomism - A term for common mapping errors that may appear when a mapper only tests maps in ZDoom, without testing in other source ports. Can also be used as a term for the quirks ZDoom exhibits that other ports do not. Comparable terms may be invented for other ports with idiosyncratic behaviors but do not tend to achieve widespread usage (the ironic "Chocolatism," referring to an unintentional deviation in Chocolate Doom, would be an example).