Speedrunning is defined by the community of a particular game or category, so these definitions may vary slightly between games. Additionally, each community may use specialized terms describing phenomena unique to that game. Many common tricks will have shorthand names derived from the part of the game they’re in, the name of the runner who discovered them, or inside jokes. The terms below are fairly universal and apply across communities.

100%: doesn’t always mean 100%. Typically means completion of all the objectives displayed on a status screen or something similarly countable. Sometimes means collection of absolutely all items, unlockables, etc. Will be defined by each game’s community.

Any%: Generally the category with the fewest rules and no completion requirements. Different communities will still define this category in specific ways, especially when determining what is sufficient for an ending.

Broken Game: Some runners and commentators will call a game with many exploits a "broken game" or describe a particular feature in a game a "broken system" if it is easy to produce unintended results. Some games are famous for being buggy even on casual playthroughs, but others are only really "broken" after unusual and deliberate actions by the player. (Developers work hard!)

Category: Each distinct set of rules for which records are kept are known as “categories.” Categories are defined by each game’s community. Any player can create a new category by defining the rules and completing a run within those rules.

Emulator: an application designed to mimic (or “emulate”) a game console on a different computer. Many consoles and older PC’s run on different processor architectures than modern computers, which is one reason that some emulators -- even those in development for decades -- are inaccurate. Emulation takes significantly more processing power than the equivalent processor on the original hardware. In the late 2010s Sony and Nintendo released official emulator-based consoles of their early home systems.

Framerate: the number of frames per second that a console or graphics card outputs to a display. Framerate variations can affect how quickly a runner can complete a game, how easy is to perform a trick, and in some games can even alter the game’s logic. Framerates can vary considerably between different PCs, consoles, and emulators.

Frame-perfect trick: Some tricks require an input on exactly one frame to be performed correctly, also called “one-frame tricks.” Similarly, tricks which can be performed on only one of two frames are called “two-frame tricks,” on one of three frames “three-frame tricks,” etc.

Glitch: When the game does not behave as the developer intended. Glitches are sometimes caused by minor bugs or oversights which a player can exploit to produce a desired result. Games are complex pieces of code, designed for complex hardware, and are usually produced under tight deadlines. Accordingly, most games have some glitches, although some require unusual and precise setups.

Glitchless: doesn’t always mean glitchless, but generally disallows at least some glitches which are allowed in other categories. There are categories for some games such as “No Major Glitches” to distinguish from true glitchless runs.

Hitbox: Often describes the boundary around a character model or object in a game which is used for collision detection. Hitboxes generally conform to the visible outline of an object on screen, but can be slightly different in many cases.

IL: "Individual Level" runs are focused on completing a single level in a game, as opposed to the entire game.

In-Game Time: Some games measure the time directly in a game. In-game timers can be inaccurate for a number of reasons. Communities will differ on whether to use in-game time or real-time for certain categories.

Intended Behavior: Usually describing what the game developers intended a player to do, as opposed to certain speedrun strats which produce unintended results.

Input Lag: There is always a delay between when a button is pressed, when a system receives that input, and when that input translates into display output, and when the display actually shows that output. In many cases, this process happens so quickly that the time delay is imperceptible. However, input lag and display lag can be noticeable depending on the system, controller, and display being used. Many runners try to minimize this lag as much as possible.

Lag: Framerate slowdown caused by excessive demands on the processor and/or memory of a system. Can be a major concern for fast times and many speedrunners focus on reducing lag as much as possible. In some instances, lag can be beneficial or allow for glitch exploits.

Meme run/Meme category: Some categories are intentionally bizarre and not generally accepted as a serious competitive run, but are intended to be purely entertaining.

NTSC: Television standard in North America, Japan, and a few other countries. Stands for “National Television System Committee.” Generally 29.97 frames per second, 59.939hz refresh rate.

OOB (Out of Bounds): Definitions will vary by game, but generally exploiting imprecise collision detection between the boundaries in a game and the player model in order to move outside of where the developers intended. “No Out of Bounds” categories often have different definitions of what constitutes out of bounds based on the game’s community.

PAL: Television standard in Europe, stands for “Phase Alternating Line.” A complex standard involving many variations, but the primary concern for retro gamers is that it is usually 25 frames per second, with a 50hz refresh rate.

PAL-M: Brazilian PAL standard which in some ways is more similar to NTSC than PAL. Can wreak havoc on capture card software and televisions. Generally 30 frames per second, 60hz refresh rate.

Pause Buffering: rapid pausing and unpausing for the purpose of sending different inputs on subsequent frames, which would normally not be humanly possible.

PR/PB: Personal record, personal best. Many runners are driven by improving their personal best times moreso than the prospect of achieving a world record.

Randomizer: Some ROMhacks take the items in popular games and randomize their locations so that long-time players can experience a new challenge. Randomizers are frequently used in competitive races.

Real-Time/RTA: Timing based on an external timer, as opposed to an in-game timer, is considered real-time. "Real Time Attack" or "RTA" is used in some communities to describe these runs.

ROMs: ROMs, short for “read only memory” describe both a type of memory chip common to many early cartridge-based systems as well as a generic term for a computer-readable data file of the contents of a game cartridge. ROMs can be loaded onto “flash cartridges” to be read by the original system or can be played on an emulator.

ROMhack: ROMhacks are modifications of ROMs which range from small tweaks to new translations to complete overhauls which are practically new games. Some ROMhacks, especially “kaizo” hacks of Super Mario Bros. games, become popular enough to be speedrun regularly.

RNG: short for “Random number generation,” although widely used to describe the amount of chance involved in a trick or a speedrun, whether or not the game is strictly generating a random number.

RNG Manipulation: Some events in games are dependent on external factors or a single seed. It is sometimes possible to manipulate the game in various ways to produce a consistent seed or consistent results in areas which otherwise were dependent on chance.

Route: Both the path a player takes through the game as well as the order in which tricks might be performed. Routing is the process of optimizing a route in practice to improve a speedrun time.

Seed: various uses. Many randomizer ROMhacks depend on the generation of a number at startup known as a “seed.” This number determines the placement of all items consistently, so two runners using the same seed will be racing the same generated map. Often used in randomizer races.

Strat: short for “strategy.” see also Tech.

TAS: A “tool-assisted speedrun” is generally performed on an emulator or a ROMhack with savestates, allowing the construction of a theoretically perfect run. TAS runs are often not possible for a human to perform in their entirety but can be studied to develop new strats.

Tech: short for “technique.” See also Strat.

TWR: Tied World Record. A world record which has been tied by at least one other person.

UWR: Untied World Record. A world record which has not yet been tied.

WR: World Record. The fastest recorded time for a given category.

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