The act of completing a video game as quickly as possible.
The most popular variety is RTA (Real-Time Attack), in which the runner completes a category in a single sitting without help from external tools, competing on online leaderboards. Another popular variety is TAS (Tool-Assisted Speedrun/Superplay), a run that is carefully assembled in an emulator with the help of savestates and other tools.
Most games have multiple categories, such as "any%" for reaching an ending to the game as fast as possible, and "100%" for completing all content a game has to offer first. Games, especially more popular ones, may have additional categories with more specific levels of required completion and glitches allowed.
This tag encompasses references to the act or concept of speedrunning itself (indicated by terms like "RTA" or "any%"), or to the techniques and routes used in speedruns of particular games, as well as noteworthy moments in particular runs.