A speedrun is a playthrough of a game, or a defined part of one, completed as fast as possible under an agreed set of rules, and to speedrun is to attempt such a playthrough. Times are timed, recorded, and compared on community leaderboards.
Speedrunning grew from players racing demo files and completion times in games such as Doom and Super Metroid into an organised practice with its own institutions. Communities define the categories, verify submissions, and maintain leaderboards for each game, because a time only means something against the same start point, end point, and rules. The charity marathon series Games Done Quick, running Awesome Games Done Quick and Summer Games Done Quick, brought the practice to a mass audience by staging live runs for fundraising.
A fast run is rarely just fast hands. Runners plan a route through the game, practise individual segments hundreds of times, and use every legal advantage their category allows, from movement techniques the designers intended to glitches they did not. The research is collective: one player finds a time saving, others refine it, and the record falls in steps over years.
Categories keep comparisons honest. Any percent races to the ending by any means the rules allow, 100 percent demands full completion, and modifiers such as glitchless restrict technique further. The same game can therefore hold many separate, thriving records at once.
In play"She holds the speedrun record by four seconds after two years of attempts."