Glossary

Completing an arcade game from start to finish using only a single credit — the original condition for which arcade games were balanced and the measure of mastery in Japanese arcade culture. 1-CC challenges are significantly harder than continue-assisted clears because arcade games were deliberately designed to consume quarters; a 1-CC requires knowing every enemy pattern, managing health deliberately, and not wasting a life on avoidable damage. In Japan, 1-CC achievement is documented in arcade rankings and gaming magazines and carries substantial prestige.

A term used in the 1980s and 1990s to describe a home console or computer port of an arcade game that replicated the original with no visible compromises in graphics, sound, or gameplay. True arcade-perfect ports were extremely rare before the PlayStation and Saturn era due to the hardware gap between arcade boards (which often used proprietary, expensive components) and consumer hardware. The phrase was frequently misused in marketing to describe ports with significant downgrades.

The demonstration loop an arcade machine plays while nobody is using it: title screens, high-score tables and recorded or computer-controlled gameplay designed to catch the eye of passers-by and persuade them to insert a coin. Home games inherited the idea as the demo that plays if you leave the title screen alone.

Also called colour clash: the effect on the ZX Spectrum (and some other machines) where each 8×8 block of pixels can hold only two colours. When a coloured sprite moves over a coloured background, the block takes on the sprite's colour or the background's, producing visible squares of wrong colour. Many Spectrum games avoided it by drawing the playfield in one or two colours.

A small battery inside a cartridge that keeps a block of memory powered so saved games survive when the console is switched off. On the NES it arrived with the Western release of The Legend of Zelda in 1987. The batteries were designed to last for years, but they eventually run flat, which is why many old cartridges now forget their saves.

Also known as a "brawler," the beat-em-up is a genre in which one or two players advance through linear stages by defeating waves of enemies using melee combat. The genre reached its commercial peak in the early 1990s arcade and 16-bit era with titles like Streets of Rage and Final Fight. A defining characteristic is the ability to pick up and throw objects and enemies, combined with a limited move set that becomes more expressive through timing and combination.

A marketing term coined by Sega of America in 1992 to advertise the Sega Genesis's CPU speed advantage over the Super Nintendo. The Genesis's Motorola 68000 ran at 7.67 MHz versus the SNES's 3.58 MHz, a real but contextually limited difference; the SNES compensated with superior graphics hardware including Mode 7 and larger colour palettes. "Blast Processing" became one of gaming's most enduring examples of technically-grounded-but-misleading marketing, and is now used ironically to describe any vague hardware claim.

A sequence in which the player fights earlier bosses again, one after another, usually near the end of the game. It tests everything the player has learned and was a common way to extend late stages with existing content.

An input sequence — typically entered on a title screen, pause menu, or controller — that unlocks hidden functionality in a game: extra lives, invincibility, level select, or debug tools. Cheat codes originated as developer shortcuts for testing and were frequently left active in retail releases. Their golden era was the late 1980s to mid-2000s, before persistent online connectivity made server-side validation practical. Gaming magazines and schoolyard oral tradition were the primary distribution mechanisms.

Music created using the sound synthesis hardware of vintage game consoles or computers — typically the NES APU, the Commodore 64's SID chip, the Game Boy's DMG sound chip, or the Sega Genesis's YM2612. In its original context, chiptune simply described game music composed within hardware constraints. As an active musical genre, chiptune encompasses contemporary artists who compose original music on vintage hardware or software emulations, treating the aesthetic limitations of old sound chips as compositional tools.

In graphics, removing parts of objects that fall outside the visible area. In everyday use the word usually means an error in collision: a character or camera passing through a wall or floor that should be solid. "No-clip" cheats deliberately switch collision off so the player can fly through the level.

The code that decides when two objects touch — a bullet hitting an enemy, a player landing on a platform. Games usually check simplified shapes such as boxes rather than exact pixels, which is why a hit can feel generous or unfair. Many famous glitches, from clipping through walls to wall jumps, come from edge cases in collision code.

The option to resume after losing all lives rather than starting over. In arcades a continue meant inserting another coin — a "credit" — within a countdown; at home, games offered a limited number of continues or unlimited ones with a penalty such as losing points. Clearing a game without continuing is a common badge of skill (see 1-CC).

A short animated introduction screen prepended to a pirated game by the cracking group responsible for removing its copy protection. Cracktros served as calling cards for groups competing for prestige within the demo scene's adjacent piracy subculture, displaying the group's name with as much graphical and musical flair as possible. Many cracktro coders went on to join legitimate demo groups; the aesthetic vocabulary of the cracktro — scrolling text, plasma effects, tracker music — directly influenced the broader demo scene.

A software post-processing effect applied to retro game emulation to simulate the visual characteristics of a CRT television: scan lines, phosphor glow, slight geometry curvature, and colour bleed between adjacent pixels. CRT filters range from simple scan-line overlays to sophisticated GPU shaders (such as CRT-Royale and CRT-Geom) that model the physics of aperture grille and shadow mask CRT panels. Many pixel-art games were designed with CRT display in mind, and their low-resolution sprites rely on colour bleed to produce smooth gradients.

A non-interactive sequence that interrupts play to tell the story, introduce a character or show the result of an action. Early examples were short animated interludes; CD-ROM storage made long pre-rendered and full-motion-video cutscenes common in the 1990s.

A subculture of programmers, artists, and musicians who create "demos" — non-interactive audio-visual programs designed to showcase technical skill on constrained hardware. The demo scene originated in the Amiga and Commodore 64 communities of the mid-1980s and produced some of the most technically impressive programming of the era, achieving real-time 3D rendering, audio synthesis, and visual effects that commercial games could not match. Demo parties such as Assembly (Finland) and Revision (Germany) remain active annual events.

Arranging pixels of two colours in a fine pattern to suggest a third colour or a transparent effect. On consoles connected by composite or RF video, the blurring of the signal blended dithered patterns into smooth shades, a trick widely used on the Mega Drive. On a sharp modern display the same graphics show their checkerboards.

Draw distance is how far into a 3D scene the game renders objects. Early 3D hardware could not draw distant scenery, so objects appeared suddenly as the player approached — "pop-in". Developers hid the limit with fog or darkness, a constraint that became part of the look of many fifth-generation games.

A hidden message, feature, image, or joke embedded in a game (or other software) by its developers, discoverable only through non-obvious actions the game does not document. The term originates from the first recognised video game Easter egg: Warren Robinett's hidden room in Adventure (Atari 2600, 1980), where his name appeared after an elaborate sequence of steps. Easter eggs differ from cheat codes in that they typically have no gameplay function — they exist purely as developer self-expression or tributes.

Software that replicates the hardware behaviour of one computing system on another, allowing software designed for the original system to run unmodified on different hardware. Game console emulators model the CPU, memory bus, graphics processor, sound hardware, and input systems of the target machine. High-accuracy emulators like Higan (Super Nintendo) and Mesen (NES) prioritise exact hardware reproduction over performance, while others optimise for playability. Emulation is legally and ethically complex: the software is generally legal, while distributing copyrighted ROMs is not.

An additional attempt awarded to the player, often as a pick-up or for reaching a score threshold. Lives came from arcade games, where a set number of attempts per coin limited how long one credit could last; home games kept the system as a measure of progress and tension.

An unofficial translation of a game, made by players and distributed as a patch to the original ROM. Fan translators opened up many Japan-only games to Western players, sometimes years before any official release, and the work often involves reverse-engineering the game's text system and fonts as much as translating it.

Frequency modulation synthesis: generating sound by using one waveform to modulate the frequency of another, producing complex timbres from very little data. Yamaha's FM chips gave the Mega Drive, Japanese computers and PC sound cards their characteristic metallic, punchy sound, distinct from the simple square waves of earlier machines and the sampled sound that followed.

Pre-recorded video, often of real actors, played back inside a game. The arrival of CD-ROM in the early 1990s made storing video practical, and a wave of "interactive movies" followed. Most offered limited interaction, but FMV cut-scenes became a standard part of CD-era games.

Numerical data describing how many frames each action in a game requires, typically expressed as startup frames (before the action is active), active frames (when it can hit), and recovery frames (during which the character is vulnerable). Frame data is most critically important in fighting games, where the difference of one or two frames determines whether a combo is possible and whether a move is "safe on block." Public frame-data spreadsheets and in-game training modes now expose this data officially; before internet resources, it was extracted by frame-counting VHS recordings.

How many times per second a game updates the image, measured in frames per second (fps). Most 8- and 16-bit games ran at 60 fps on NTSC televisions (50 on PAL) because their logic was tied to the display; many early 3D games ran at 30 fps or less because each frame took more work. Smooth, consistent frame rates matter most in fast action and fighting games.

Blocking access to an area until the player has a particular ability, item or story event — a locked door, a gap too wide to jump, a ledge too high to reach. Gating lets designers control the order of exploration in open structures and is central to Metroid-style games, where new abilities open paths that were visible all along.

The practice of systematically searching a game for programming errors that produce unintended behaviour — out-of-bounds movement, memory corruption, frame-perfect collision bypasses, or duplication exploits. Glitch hunters use emulator debugging tools, memory viewers, and frame-advance to isolate the exact conditions that trigger an error. Their discoveries feed directly into speedrunning routes and TAS improvements, and have produced some of the most technically sophisticated community documentation in gaming.

Repeating a task — usually fighting enemies — mainly to gain experience, money or items rather than to progress the story. Grinding is closely associated with role-playing games, where players build up their characters to survive harder areas, and the word is often used to criticise a game that requires too much of it.

A playable character in a game — typically a fighting game or sports game — who does not appear in the standard character select screen and must be unlocked through specific conditions or codes. Hidden characters create long-term engagement beyond the main roster and reward dedicated players with exclusive content. The practice was popularised by Mortal Kombat's secret opponent Reptile (1992), and became a key feature of fighting games through the 1990s. Unlockable characters were largely replaced by DLC characters in the online era.

The invisible geometric shape — usually a rectangle or series of rectangles — attached to a character or object that the game's collision detection uses to determine whether two objects have made contact. A hitbox may be smaller or larger than the character's visible sprite; deliberately undersized hitboxes on player characters make them easier to control in dense environments, while fighting games use separate hitboxes for attack and vulnerability zones to allow aggressive "active frames" without immediate counter-vulnerability.

Games and software made by hobbyists for consoles and computers, usually without the manufacturer's involvement. Old platforms have large homebrew scenes producing new cartridges for systems decades after their commercial life ended. On the Vectrex, the rights holder explicitly allowed fee-free homebrew development by the mid-1990s.

The total delay between a player pressing a button and the corresponding action appearing on screen. Input lag accumulates from multiple sources: the controller's wireless or wired latency, the console's processing time, the display's internal image-processing pipeline, and the game's own input polling rate. Competitive players and speedrunners typically use CRT monitors or modern displays with "game mode" enabled to minimise lag; the difference between 1 frame (~16ms) and 4 frames (~66ms) of lag is perceptible and affects timing-critical gameplay.

A short window, measured in frames, during which a character cannot be hurt — typically just after taking damage, often shown by the sprite blinking, so that one hazard cannot drain all health at once. Some games also grant them during dodges or rolls, which players learn to use to pass through attacks.

A disc image file — a binary copy of an optical disc (CD, DVD, or Blu-ray) stored as a single file. In gaming, ISO files are ROM equivalents for CD-based and DVD-based consoles: PlayStation, Sega Saturn, Dreamcast, GameCube, and PlayStation 2 games are commonly distributed as ISO or related formats (BIN/CUE, GDI, CHD). The name derives from the ISO 9660 filesystem standard for CD-ROMs. ISOs are larger than cartridge ROMs due to disc capacity; a PlayStation 2 game ISO can be several gigabytes.

A camera angle that shows a scene diagonally from above, with the three axes drawn at equal angles, giving an impression of depth without true 3D rendering. Isometric graphics let 8- and 16-bit machines present three-dimensional spaces using ordinary sprites and tiles.

A stage or level that cannot be completed, or that crashes the game, because the program was never designed to reach it — usually because a counter overflows. Arcade games of the early 1980s assumed nobody would play long enough to find out. Pac-Man's 256th maze draws garbage over half the screen when the level counter overflows, and Donkey Kong ends on level 22 when Mario's bonus timer runs out almost immediately.

The input sequence Up, Up, Down, Down, Left, Right, Left, Right, B, A — created by Konami programmer Kazuhisa Hashimoto as a personal testing shortcut during the NES port of Gradius (1986) and accidentally left in the final cartridge. Its most famous implementation is in Contra (1988), where it grants 30 lives and enabled millions of players to finish an otherwise brutal game. The code has been referenced in over 100 Konami titles and has spread far beyond gaming into websites, films, and cultural references as a universal shorthand for secret knowledge.

A Japanese compound word combining "kuso" (crap) and "ge" (short for "game"), meaning a game of exceptionally poor quality. Unlike a simple bad game, a kusoge typically has a quality so entertainingly terrible that it becomes worth experiencing ironically — a Japanese analogue to "so bad it's good." Famicom-era Japan produced a notable catalogue of rushed kusoge, and the term has been adopted by Western retro gaming communities. Certain kusoge, like Big Rigs: Over the Road Racing, have developed cult followings precisely because of their brokenness.

A security chip that stops a console from running unlicensed games. The NES used Nintendo's 10NES system: a chip in the console and a matching chip in every licensed cartridge had to agree before the game would run, which is why a poorly seated cartridge produced the familiar blinking power light. Lockout gave Nintendo control over which companies could publish for its system.

A chip inside an NES or Famicom cartridge that switches different sections ("banks") of the cartridge's memory into the small window the console can address at once. Mappers let NES games grow far beyond the console's original design, and some, such as Nintendo's MMC3, also added features like scanline counters for split-screen effects. Emulators must reproduce each mapper to run the games that use it.

A portmanteau of Metroid and Castlevania (specifically Castlevania: Symphony of the Night), describing a subgenre of action-platformer built around a large, interconnected map where progress is gated by specific abilities or items acquired during play. The player backtracks through previously explored areas as new powers open routes that were inaccessible on the first pass, rewarding thorough exploration and map literacy.

A graphics mode exclusive to the Super Nintendo that affine-transforms a flat tile layer — rotating, scaling, and translating it in real time to create the illusion of a 3D plane. Mode 7 does not produce true 3D geometry; it projects a 2D layer at an angle, producing the perspective effect used in F-Zero's racing surface, Super Mario Kart's track, and the world map in Final Fantasy VI. The Sega Genesis had no hardware equivalent, making it a key SNES differentiator.

Starting a game again after finishing it while keeping some progress — levels, items or abilities — from the completed playthrough. Chrono Trigger popularised the name, and its New Game Plus also opened the way to many of its alternative endings.

The large, connecting map that links a game's individual locations — towns, dungeons, levels — and that the player travels across between them. In RPGs it is usually drawn at a smaller scale than the places it connects; in action-adventures such as The Legend of Zelda it is a continuous, explorable space of its own.

A game bundled in the box with a console. A strong pack-in shows off the hardware and gives every owner the same first experience; several of the best-known pack-ins became the best-selling games of their platforms because every console sold included a copy.

Reusing the same graphics with different colours to create a new character, enemy or item. Because older hardware drew sprites through colour palettes, changing the palette cost almost no memory, so palette-swapped enemies — a stronger blue version of a red monster — were everywhere in 8- and 16-bit games. Fighting games use the same technique to give two players the same character in different colours.

A technique in 2D games where multiple background layers scroll at different speeds to create an illusion of depth. Objects depicted as distant move slowly while objects depicted as near move quickly, mimicking the parallax effect observed when looking out a moving vehicle's window. The SNES and Genesis both supported multi-layer parallax; games like Sonic the Hedgehog and Super Metroid used it extensively to give flat environments a sense of spatial dimensionality.

A way of resuming a game without any save memory: the game shows a code that encodes the player's progress, and entering it later restores that state. Passwords were cheaper than battery-backed memory and common on the NES, Master System and Mega Drive. Because the codes were just data, players could also find or construct codes for states the designers never intended.

An arcade game's tendency to drain coins, typically through high difficulty, sudden deaths or tempting continues. Arcade design balanced challenge against revenue: a game that ended too quickly drove players away, one that lasted too long on one coin earned little. Many home ports kept the arcade difficulty but gave unlimited continues.

A shooting game in which the camera or vehicle moves along a fixed path, as if on rails, while the player concentrates on aiming and firing. The format suits light-gun games and on-rails 3D shooters, where the designer controls exactly what the player sees.

Measures that stop games from one territory working on consoles from another. Some were physical — Japanese Super Famicom cartridges are a different shape from North American SNES cartridges — while others relied on lockout chips or region codes read by the system. Region locking protected separate release schedules, prices and licensing deals, and created the market for import adapters.

A genre derived from Rogue (1980), characterised by procedurally generated dungeons, permadeath (losing all progress on death), and turn-based tile movement. The Berlin Interpretation — a community-defined set of criteria — codifies the "true roguelike": ASCII or simple tile graphics, grid-based movement, and complex systems that interact in unpredictable ways. Every run generates a different dungeon layout, making mastery a function of systems knowledge rather than level memorisation.

A game that borrows roguelike elements — procedural generation, run-based structure, and permadeath — but relaxes the strict Berlin Interpretation criteria, often incorporating persistent unlocks, real-time action rather than turn-based movement, or meta-progression that carries across deaths. The roguelite is commercially dominant over the "pure" roguelike; games like Hades and Dead Cells use procedural generation to create replayability while allowing players to permanently strengthen their character between runs.

Read-Only Memory — in gaming contexts, a digital file containing an exact binary copy of a game cartridge's ROM chips. A ROM file preserves the complete software content of a cartridge and can be loaded by an emulator to run the game on modern hardware. The legal status of ROM files is contested: dumping a ROM from a cartridge you own occupies a legal grey area, and distributing or downloading ROMs of games still under copyright is infringement in most jurisdictions. Preservation organisations argue ROMs are essential for archiving games that are no longer commercially available.

A technique, common in racing games, that keeps computer-controlled opponents close to the player: rivals who fall behind speed up and leaders slow down, as if tied together with a rubber band. It keeps races close but can feel unfair when an opponent catches up impossibly fast.

A side-scrolling action genre in which a player-controlled character moves forward through levels while shooting horizontally and jumping over obstacles, maintaining constant forward momentum under relentless enemy pressure. Contra (1987) established the genre's definitive template: large humanoid characters, multi-directional aiming, and screen-filling bosses. The genre is closely related to the SHMUP but distinguishes itself through on-foot ground-based movement rather than vehicle flight.

A fixed place in a game where progress can be saved, as opposed to saving anywhere. Save points let designers control pacing and tension — the distance between them is part of the difficulty — and were also a practical response to limited save memory on consoles.

An emulator feature that captures a complete snapshot of the emulated hardware's state — CPU registers, RAM contents, GPU state, audio buffers — to a file, allowing the player to restore that exact moment at any time. Save states are not a feature of original hardware; they exist only in emulation. They are invaluable for preservation testing and TAS creation, and controversial for casual play: they enable progression through games originally designed around lives-and-continues pressure but fundamentally alter the difficulty contract those games were built on.

The horizontal dark lines visible on CRT televisions between rows of phosphor pixels, produced by the electron beam's discrete scan pattern. Scan lines are a physical property of CRT display technology, not an artistic choice; they became aesthetically associated with retro games because all games before the early 2000s were designed to be displayed on CRTs. Modern displays render each pixel at full brightness without gaps, which some players find harsher than the soft, scan-line-filtered image that developers originally intended.

One horizontal line of a television picture. A CRT draws the image line by line, top to bottom, and older game hardware generated its picture in step with that beam. Many graphical tricks — changing colours, scroll positions or sprites partway down the screen — work by altering settings between scanlines, and many hardware limits, such as sprites per line, are counted per scanline.

A contraction of "shoot 'em up," a SHMUP is a game in which the player controls a vehicle or character that moves through a field of enemy fire, shooting back to survive. The genre divides into vertical scrollers (Galaga, 1942), horizontal scrollers (R-Type, Gradius), and "bullet hell" or danmaku games (Touhou, Ikaruga), where the screen is flooded with elaborate patterns of projectiles that demand memorisation and precise movement.

Low-effort software released in volume to exploit a popular platform, licence or format — "shovelled" onto shelves or discs with little regard for quality. The term originally described CD-ROM compilations padded with any software that would fit, and later came to mean cheap games of any kind.

A drop in game speed that happens when the processor cannot finish all the work for a frame in time — typically when the screen fills with enemies, bullets or explosions. Older games ran their logic once per frame, so a missed frame slowed the whole game rather than just its animation. On many shooters it became an accepted, even welcome, part of play in the busiest moments.

A soft reset returns a game or console to its initial startup state via software — typically by pressing a specific button combination on the controller — without cutting power to the hardware. Many SNES games accept L + R + Start + Select pressed together as a soft reset. Soft resets were important before battery saves became universal, as they allowed quick restarts without physical manipulation of the hardware. In speedrunning, the soft reset is used to restart a run without the full console boot sequence, saving several seconds.

A subgenre of action RPG defined by the design philosophy introduced in Demon's Souls (2009) and refined in Dark Souls (2011): high difficulty calibrated around pattern recognition, sparse and cryptic narrative delivered through item descriptions and environmental storytelling, and a resource-loss mechanic that punishes death without ending the run. The term is now applied broadly to any game sharing this difficulty philosophy and feedback loop.

A menu, often hidden, that lets players play a game's music and sound effects individually. Sound tests were common on 16-bit consoles and frequently doubled as the place to enter cheat codes — Sonic the Hedgehog 2's level select is unlocked by playing particular sounds in the sound test.

A playthrough of a game completed in the fastest possible real-world time, often exploiting glitches, sequence breaks, and optimised movement that fall outside the game's intended play path. Speedrunning has a formal competitive infrastructure: Speedrun.com tracks world records across thousands of games in multiple categories (Any%, 100%, Glitchless). Charity marathons like Awesome Games Done Quick have made speedrunning a broadcast spectacle, with runs routinely watched by hundreds of thousands of viewers.

A small two-dimensional image that can be moved independently over a background — a character, enemy, bullet or item. Many consoles and computers of the 1980s and 1990s had hardware dedicated to drawing sprites, so the processor only had to update their positions rather than redraw them. Hardware limits on how many sprites could appear at once, or on one line, shaped how games of the era looked.

A visual artefact caused by hardware limits on how many sprites can appear on one horizontal line. The NES can draw only eight sprites per scanline; when more are needed, games rotate which ones are drawn each frame, so objects appear to blink rather than vanish completely. It is a deliberate workaround, and on a CRT at 60 frames per second it was the lesser evil.

The hardware ability to resize a sprite in real time, enlarging or shrinking it to simulate depth or produce special effects. Early arcade hardware like Sega's Super Scaler boards (OutRun, After Burner) used dedicated scaling chips to create the illusion of 3D movement by enlarging approaching sprites and shrinking receding ones. The technique was computationally expensive on home hardware; its quality was often a key differentiator between console ports of scaling-intensive arcade games.

A recorded game playthrough created using emulator tools that allow frame-by-frame input editing, save-state rewinding, and slow-motion — producing a theoretically perfect run that no human could execute in real time. TAS runs demonstrate the absolute performance ceiling of a game; they reveal glitches and routes that human speedrunners then study and attempt to replicate partially under normal conditions. TASVideos.org is the central archive for the format. TAS runs are clearly labelled as tool-assisted and are not considered legitimate human records.

The bending and swimming of textures on early 3D surfaces, most familiar from the PlayStation. Its renderer used affine texture mapping, which does not correct for perspective, so textures on large polygons distort as the camera moves. Developers reduced it by splitting surfaces into more, smaller polygons. Combined with jittering vertex positions, it is part of the recognisable look of the console.

Building screens out of small reusable blocks — typically 8×8 pixels — rather than storing every pixel. A background is described as a map of tile numbers, so a large level needs only a small set of unique tiles. Consoles from the NES to the SNES and Mega Drive were designed around tiles, which is why their worlds are made of repeating blocks, bricks and platforms.

Music composed in a "tracker" — software that presents music as a vertical pattern grid where each column represents a channel and each row represents a unit of time. The format originated with Ultimate Soundtracker on the Amiga in 1987 and became the dominant method for composing music on the Amiga, and later for PC demo scene productions. MOD, S3M, XM, and IT are common tracker file formats; tracker music is notable for embedding both the composition and the instrument samples in a single small file.

Software or hardware that is announced, sometimes promoted for years, but never released — or released so late that the wait becomes the story. The games industry's best-known case is Duke Nukem Forever, announced in 1997 and released in 2011.

A "volume pixel": a value on a regular three-dimensional grid. In 1990s games, voxel-style techniques were used mostly to draw detailed landscapes from height maps, producing rolling terrain that polygon hardware of the time could not match.

A flickering artefact in 3D graphics when two surfaces sit at almost exactly the same depth, so the renderer cannot decide which one is in front and alternates between them from frame to frame. It is common where a decal or texture is laid very close over another surface.