Speedrunning is reverse engineering by another name. The game gives you a designed path. Speedrunners find every crack in it, test every assumption the developers made, and build a completely different path that the designers never intended. The results are sometimes astonishing: games completed in minutes that take most players dozens of hours, sequences skipped entirely through mechanics the engine was not built to prevent.
The categories that define the practice
Any% means finishing the game by any means available — all glitches, all skips, all exploits permitted. It produces the fastest times and the most technically complex routes. It is also the category most likely to look completely incomprehensible to someone who has never played the game, because the route bears almost no resemblance to normal play.
100% requires completing the game fully: all items, all collectibles, all objectives. It produces longer runs but often more impressive ones in terms of game knowledge, because the runner must know every corner of a game rather than optimising a narrow critical path through it.
Glitchless restricts the run to movement and mechanical skill without exploiting engine bugs. It is closest to what developers intended and often produces runs that look more like skilled normal play at extreme speed. Some players prefer these for their watchability.
The specific techniques that appear in most games
Out of bounds exploits use engine seams — places where collision detection fails — to move through geometry that should be impassable. Many open-world games have invisible walls that define the intended play area; speedrunners find the edges where those walls have gaps.
Wrong warps exploit sequence dependencies in game logic. Many games load the next area when a specific flag is triggered. Triggering that flag in an unintended order can warp the player to a later area that was only supposed to be reached after significant progress. The original Legend of Zelda had a warp that skipped most of the game through a specific exploit discovered in the early 1990s.
Arbitrary Code Execution (ACE) is the most extreme technique: exploiting memory corruption bugs to inject code into the game’s running process, effectively programming the game to do whatever the runner wants. The original Pokemon Red can be completed in under eight minutes through ACE. The technique requires understanding the game at the level of machine memory addresses, not game mechanics.
What Games Done Quick demonstrated
The Games Done Quick charity marathons — AGDQ in January and SGDQ in summer — have raised over $50 million for charity since 2010. More significantly for the practice of speedrunning, they made it a spectator sport. Watching a runner explain what they are doing while doing it, calling out the difficult sections in real time, and occasionally failing a trick that the audience understands the difficulty of — this is genuinely compelling viewing for a mainstream gaming audience that does not speedrun themselves.
Speedrunning communities exist around Speedrun.com and within Discord servers for specific games. The knowledge sharing within these communities — the detailed documentation of routes, techniques, and the physics engine behaviour that makes them work — is among the most technically thorough analysis of any games that exists anywhere.
