Speedrunning takes various forms, especially in the retro scene. Some seek to make 'pure' runs as quickly as possible, while others exploit loopholes in game code to find shortcuts and warps that drastically cut a run's time. A recent discovered for The Legend of Zelda on the Famicom Disk System is in the latter category, and in theory allows the game to be cleared in under three minutes.
The workaround was discovered by speedrunner and programmer Sockfolder, who has identified a warp that can only be achieved in version 1.1 of the Famicom Disk version; it won't work on a NES copy. In setting up specific file names, including the famous 'Zelda' entry to skip to the second dungeon, it's possible to manipulate the game's code and cause it to lose its way and warp the player right to Zelda's room at the end of the game.
Doing this requires careful play, triggering an excess of sprites in a specific area before using the whistle at a key point. It's rather tricky and precise, meaning that it'll be limited to the most skilled speedrunners,
The video below by MagicScrumpy breaks it all down in detail, explaining what's happening to the game's code as the trick is executed.
It's another intriguing discovery - it's amazing what enthusiasts find and achieve when working with retro hardware and its limitations.