Editing Tool-assisted speedrun

{{short description|Video game technique}}
{{Multiple issues|
{{More citations needed|date=February 2014}}
{{Notability|date=July 2024}}
{{Citation style|date=November 2015}}
}}
{{Use mdy dates|date=July 2024}}
A '''tool-assisted speedrun''' or '''tool-assisted superplay''' ('''TAS'''; {{IPAc-en|t|æ|s}}) is generally defined as a [[speedrun]] or [[playthrough]] composed of precise inputs recorded with tools such as [[video game emulator]]s. Tool-assisted speedruns are generally created with the goal of creating theoretically perfect playthroughs. This may include the fastest possible route to complete a game or showcasing new optimizations to existing [[world record]]s.

TAS requires research into the theoretical limits of the games and their respective competitive categories. The fastest categories have no restrictions and often involve a level of gameplay impractical or impossible for a human player, and those made according to [[real-time attack]] rules serve to research the limits of human players.

The TAS developer has full control over the game's movement, per video frame, to record a sequence of fully precise inputs. Other tools include [[Saved_game#Save_states|save states]] and branches, rewriting recorded inputs, splicing together best sequences, [[Macro (computer science)|macros]], and [[Script (computer programming)|scripts]] to automate gameplay actions. These tools grant TAS creators precision and accuracy beyond a human player.

==History==
The term was coined during early ''[[Doom (1993 video game)|Doom]]'' speedrunning. When Andy "Aurican" Kempling released a modified version of the ''Doom'' source code that made it possible to record demos in slow motion and in several sessions, it was possible for the first players to start recording tool-assisted demos. In a few months, in June 1999, Finnish Esko Koskimaa, Swedish Peo Sjöblom, and Israeli Yonatan Donner opened the first site to share these demos, "Tools-Assisted Speedruns".

In 2003, a video of a Japanese player named Morimoto completing the [[Nintendo Entertainment System|NES]] game ''[[Super Mario Bros. 3]]'' in 11 minutes and performing stunts started floating around the Internet. The video was controversial, because not many people knew about tool-assisted speedruns, especially for the [[Nintendo Entertainment System]]. The video was not clearly labeled as such, so many people considered an [[emulator]] cheating. It inspired Joel "Bisqwit" Yliluoma to start the NESvideos website for TAS for the NES, and it was renamed TASVideos.

Tool-assisted speedruns have been made for some [[ROM hacking|ROM hacks]] and for published games. In 2014, the speedrunning application [[TASBot]] was developed, capable of direct controller input.<ref name=":1">{{Cite news |last=Orland |first=Kyle |date=January 5, 2015 |title=Pokémon plays Twitch: How a robot got IRC running on an unmodified SNES |work=Ars Technica |url=https://arstechnica.com/gaming/2015/01/pokemon-plays-twitch-how-a-robot-got-irc-running-on-an-unmodified-snes/ |access-date=September 18, 2019}}</ref>

==Method==
Creating a tool-assisted speedrun is the process of finding the optimal set of inputs to fulfill a given criterion&nbsp;— usually completing a game as fast as possible. No limits are imposed on the tools used for this search, but the result has to be a set of timed key-presses that, when played back on the actual console, achieves the target criterion. The basic method used to construct such a set of inputs is to record one's input while playing the game on an emulator, all the while saving and loading the emulator's state repeatedly to test out various possibilities and only keep the best result. To make this more precise, the game is slowed down. Initially, it was common to slow down to some low fraction of normal speed. However, due to advances in the field, it is now expected that the game is paused during recording, with emulation advanced one frame at a time to eliminate any mistakes made due to the urgency.

The use of savestates facilitates luck manipulation, which uses player input as [[Entropy (computing)|entropy]] to make favorable outcomes. Examples include making the ideal piece drop in ''[[Tetris]]'', or getting a rare item drop from a defeated enemy.

===Re-recording emulators===
Tool-assisted speedrunning relies on the same series of inputs being played back at different times always giving the same results. The emulation must be [[deterministic]] with regard to the saved inputs, and [[random seed]]s must not change. Otherwise, a speedrun that was optimal on one playback might not even complete it on a second playback. This desynchronization occurs when the state of the emulated machine at a particular time index no longer corresponds with that which existed at the same point in the movie's production. Desyncs can also be caused by incomplete savestates, which cause the emulated machine to be restored in a state different from that which existed when it was saved. Desyncs can also occur when a user attempts to match inputs from an input file downloaded from TASVideos and fail to match the correct enemy reactions due to bad AI or RNG.

===Verification===
Some players have fraudulently recorded speedruns, either by creating montages of other speedrun or altering the playing time, posting them as TAS or RTA. Because tool-assisted speedruns can account for all aspects of the game code, including its inner workings, and press buttons precisely and accurately, they can be used to help verify whether an unassisted speedrun record is legitimate.

One of the best-known cases is [[Billy Mitchell (gamer)|Billy Mitchell]], whose [[Donkey Kong (arcade game)|''Donkey Kong'']] and ''[[Pac-Man]]'' [[Guinness World Records|Guinness records]] were revoked in 2018, because he used the emulator [[MAME]].<ref>{{Cite web |last=Crecente |first=Brian |date=April 13, 2018 |title=Guinness World Records Disqualifies Billy Mitchell's Perfect 'Pac-Man' Run, Other Achievements |url=https://variety.com/2018/gaming/news/billy-mitchell-pac-man-world-record-1202752594/ |access-date=July 26, 2020 |website=Variety |language=en}}</ref>

In 2018, the world record for [[Dragster (video game)|Dragster]] by [[Todd Rogers (gamer)|Todd Rogers]] was removed from [[Twin Galaxies]] and [[Guinness World Records|Guinness records]] after an experiment showed that his 5.51 second time was impossible to achieve even with a TAS.<ref>{{Cite web |title=Dragster Designer David Crane Has No Doubts Of Todd Rogers' Record [UPDATED] |url=https://www.twingalaxies.com/feed_details.php/87/Dragster%20Designer%20David%20Crane%20Has%20No%20Doubts%20Of%20Todd%20Rogers%27%20Record%20[UPDATED]/1 |access-date=May 29, 2021 |website=www.twingalaxies.com |language=en}}</ref><ref>{{Cite web |last=Frank |first=Allegra |date=January 29, 2018 |title=Longest-standing video game record declared 'impossible,' thrown out after 35 years (update) |url=https://www.polygon.com/2018/1/29/16944736/atari-dragster-game-world-record-banned |access-date=May 29, 2021 |website=Polygon |language=en}}</ref>

==Examples==
In ''[[Super Mario Bros.]]'', the current Famicom and NES human-theory world record, created by Maru, stands at 4:57.54 (4:54.265 in RTA timing).<ref>{{cite web |url=https://kotaku.com/speedrunner-smashes-a-computer-assisted-super-mario-bro-1834457319 |title=Speedrunner Smashes A Computer-Assisted Super Mario Bros. Record By A Single Frame |first=Natalie |last=Degraffinried |publisher=[[Kotaku]] |date=May 1, 2019 |access-date=March 22, 2023}}</ref> In ''[[Super Mario Bros. 3]]'', arbitrary code execution along with credits warp allows injecting a [[ROM hacking|hack]] that simulates a [[Unix-like]] console, providing extra features to Mario. The current TAS standing at 216 milliseconds (13 frames) was performed by exploiting a small bug with the Famicom and NES hardware in which the CPU makes many extra "read" requests from one of the controller inputs, registering many more button presses than have occurred; the A button is mashed at a rate of 8 [[kilohertz]] (8000 times per second), performing the credits warp glitch.<ref>{{Cite web |last=Orland |first=Kyle |date=July 12, 2016 |url=https://arstechnica.com/gaming/2016/07/how-to-beat-super-mario-bros-3-in-less-than-a-second/ |title=How to beat Super Mario Bros. 3 in less than a second |website=[[Ars Technica]] |access-date=December 22, 2023}}</ref> In ''[[Super Mario World]]'', arbitrary code execution allows injection of playable versions of ''[[Flappy Bird]]'',<ref>{{Cite web |title=Streamer transforma Super Mario World en Flappy Bird |url=https://www.levelup.com/noticias/365797/Streamer-transforma-Super-Mario-World-en-Flappy-Bird |access-date=July 30, 2020 |website=LevelUp |date=March 28, 2016 |language=es}}</ref> ''[[Pong]]'', [[Snake (video game genre)|''Snake'']], and ''[[Super Mario Bros.]]''

==See also==
*[[Time attack]] — a mode which allows the player to finish a game (or a part of it) as fast as possible, saving record times.
*[[Score (game)|Score attack]] — the attempt to reach a record logged point value in a game.
*[[Electronic sports]] — video games that are played as competitive sports.
*[[Piano roll]]
*''[[Meta Runner]]'' — an animated web series inspired by the tool-assisted speedruns.

==References==
{{reflist}}
*{{Cite web |last=Turner, B. |year=2005 |title=Smashing the Clock |url=http://www.1up.com/do/feature?cId=3142599&did=1 |access-date=January 10, 2010 |publisher=1UP.com}}
*{{Cite web |last=Totilo, S. |year=2006 |title=Gamers Divided Over Freakish Feats Achieved With Tool-Assisted Speed Runs |url=http://www.mtv.com/news/articles/1528811/20060417/index.jhtml |archive-url=https://web.archive.org/web/20070213182929/http://www.mtv.com/news/articles/1528811/20060417/index.jhtml |url-status=dead |archive-date=February 13, 2007 |access-date=January 10, 2010 |publisher=MTV News}}

==External links==
* [http://tasvideos.org TASVideos] tool-assisted speedruns and resources

{{Speedrunning}}

{{DEFAULTSORT:Tool-Assisted Speedrun}}
[[Category:Speedrunning]]
[[Category:Video game terminology]]
[[Category:Cheating in video games]]