Mugen (game engine)

For other uses, see Mugen.

File:Mugen0.png

M.U.G.E.N's default motif. Many different looks are possible for the engine.

M.U.G.E.N is a freeware 2D fighting game engine designed by Elecbyte, written in C with the Allegro library. The engine was originally released in July 17, 1999. Beta versions of it were made to work on DOS, Linux and Windows platforms, distributed through their website or to donators via email. With the release of the Linux version, support for DOS ceased.(Google download mugen & you will find a site that has M.U.G.E.N for download. The chars you want you should go to YouTube to get them).

The engine allows anyone to create characters, background stages and other game objects through interpreted text files, graphics, and sound compilations. It supports various types of audio formats such as MP3, ADX, OGG and MIDI as background music during gameplay or at other points such as an introduction or the select screen. The engine allows for most of the same type of functionality found in most any commercial 2D fighting game, up to and including close recreation of those games' characters and gameplay. While the engine is set up primarily for fighting game development, several other game types have been developed using it, including shooter and platformer style games.

History

First released on July 17, 1999, M.U.G.E.N was initially created for MS-DOS. Development of the DOS version ceased when Elecbyte switched to the Linux platform in November 2001. For a time, Elecbyte had posted a request for donations on their site to legally obtain a Windows compiler to make a Windows version of M.U.G.E.N. However, the development group discontinued the project in 2003 and shut down their site. Later speculation pointed at leaks made public of a private Windows-based M.U.G.E.N beta that was provided to donators.

The WinM.U.G.E.N beta contained a two-character roster limit, locked game modes, and nag screens. A "no limit" hack that removed most of these limitations was made available in 2004, followed by subsequent updates to deal with bugs and other issues. This version of M.U.G.E.N. is functionally the same as the last Linux release. In May of 2007, a hacked version of WinM.U.G.E.N was released by a third party that added support for high resolution stages (like those seen in Guilty Gear X) at the cost of losing support to standard resolution M.U.G.E.N stages. Later that month, another hack was done to add support for hi-res select screens.

In mid 2007, Elecbyte's site returned, though not admit some controversy as to the legitimacy of it, as it only showed a single logo with Google ads on the side. On July 26, though, a FAQ was added to the site. This FAQ went on to claim that they would release a fixed version of WinM.U.G.E.N before major format changes in the next version, and noted the formating changes would remove compatability in regards to older works: "Do not expect old characters to work. At all."

These claims are still being questioned, with the possibility this is a hoax by someone who bought the domain, or someone that hacked it. Although the logo presented on the website is much different than the original logo[1]--which is subject to copyright/trademark laws--further evidence beyond speculation does not exist at this time.

Since development of the engine was halted and no source code has been made available by Elecbyte, several clone projects started to try and duplicate the functionality of the engine from scratch, such as ShugenDo and InfinityCat. Some of them present online gameplay capabilities, a feature many users have sought after.

Name

Officially, Elecbyte claims to have forgotten what the acronym M.U.G.E.N stood for, but the readme documentation states that its meaning referred to the days when the engine was meant to emulate shooting games as opposed to fighting games. There is no official pronunciation. "Mugen" (無限) in Japanese means "infinite" (lit. "no limit"), therefore mu-gen could be the suggested pronunciation. Whether M.U.G.E.N's acronym origin is simply the Japanese word Mugen, but spaced out by periods or the acronym just coincidentally spelled an existing word out is debatable. Of note also Kung Fu Man's documentation within the character's files has Japanese comments directly alongside those in English.

Gameplay

An example of M.U.G.E.N's gameplay, original character Dragon Claw faces Lei-Lei on the RAW is WAR Arena.

The engine uses 7 buttons for gameplay along with the directional keys, in order to accommodate six-button fighters, which use three punches, three kicks, and a taunt. However, characters do not necessarily use all seven buttons, nor need to follow a traditional six- or four-button format. At most, two human players can control characters, with others controlled by the engine's AI; including a demo mode where the computer controls all characters. In addition, several gameplay modes are available via the main menu.

There are three different kinds of team modes: Single, Simul, and Turns. In team mode, either side can use any of the team modes. Single is identical to not having a team, Simul gives that side a computer-controlled partner who fights simultaneously, and Turns uses a different character for each round of play. The characters' starting life will be adjusted according the number of players on each side. If one side has two characters and the other has only one in one of the Team modes, the side with two characters will each have half their respective normal maximum life values. Pre-WinM.U.G.E.N versions of the engine could have this feature adjusted or disabled via the options screen or the config file, but due to the nature of the hack, the option has not yet been reactivated.

Team Co-op is similar to Simul, except both human players fight on the same side at the same time.

In Survival mode, there is an endless stream of opponents, fighting them either one by one or two in a simul match. The objective is to beat as many opponents as possible, with the game ending when the player's team is defeated. The player can choose to play alone or in Simul or Turns mode, though single player mode gives the highest life and life recovered at the end of each round won. Survival mode was last addition done to the engine. As such, it is not present in any of the DOS versions of M.U.G.E.N.

Evidence that a fourth team mode was planned, called "tag", was revealed in the hidden programming controllers TagIn and TagOut (though only TagIn functions, and even then only if a partner is present, otherwise the engine will crash). Presumably this gameplay mode would have allowed the characters to swap out one character for another akin to Tekken Tag or games in the Marvel VS. series, though this is only speculation based off the functionality of the hidden TagIn script controller (which could change the state of both the player and his partner). It is uncertain just why Tag never became an accessable option: no mention of it is given at all in the documentation.

Noteworthy Engine Content

Original characters

There were two characters made by Elecbyte directly themselves, though only one of which had ever seen existence in M.U.G.E.N.

File:Kungfuman.png

Kung Fu Man

The first, and only, character created for the engine by its creators, Elecbyte. Kung Fu Man (typically shortened to just "KFM"), despite his name, is a practitioner of karate (as can be seen from his moves as well as his outfit). One day, he was walking with his girlfriend when Suave Dude and his minions kidnapped the girl, and retreated to their mountain temple. KFM soon followed, only to come face-to-face with a clone of himself created by Suave Dude. Although the original won the ensuing battle, Elecbyte had not made Suave Dude as a character yet, and he was left to simply wait "until next time".

His appearance is that of a man in a gi with a black shirt underneath, blue shoes, headband, hair standing straight up, and closed eyes (similar to Goro Daimon, Akira Yuki, or Brock).

As the engine's development progressed, so did Kung Fu Man, gaining the occasional new move, implementing newly created engine features, and at one point sporting an improved look. His story was never actually fleshed out by Elecbyte themselves, leaving him to be a template character of everyone else to use as a base for their own characters. With such a generic name, perhaps it was not the intention of Elecbyte to make him a complex character.

Many alternate versions of Kung Fu Man have been made for the engine by creators, quite possibly more than any other character. As a result he has become an icon of sorts for M.U.G.E.N itself.

File:Suavedude.png

Suave Dude

Suave Dude is the antagonist of Kung Fu Man's storyline. Although a sprite of him exists, Elecbyte never made the character, nor has anyone else in the Mugen community. This nonexistence of a Suave Dude character to fight is made light of in Kung Fu Man's ending, which has sad and sulk in a corner. He has an interest in Kung Fu Man's girlfriend, and created the clone KFM fights in his storyline.

Maxine

Maxine is a character programmed and sprited by Andrés Borghi. It has signifigance as being the first known commissioned M.U.G.E.N character, paid for and concepted by Maximo Perez. This fact about the character has since brought up questions regarding the selling and marketability of M.U.G.E.N works.

U.N.I.T.E.D

The Characters found in the U.N.I.T.E.D (Unofficial New Invincible Testp EnhanceD) fighting game; Xia Hou Dun, Shinobu, Blue Mary, Ryuri, and Guile; have been considered to be authored by Elecbyte under the moniker T.E.S.T.P (The Enhanced Special Testing People). The true authorship of the game is unknown, but T.E.S.T.P used private betas distributed by Elecbyte to make releases coincide roughly with new revisions of the M.U.G.E.N engine. The filestamps of the characters Xia Hou Dun and Shinobu predate the first release of M.U.G.E.N by four months. T.E.S.T.P also presented much of the same ideology that Elecbyte had in providing the work files for all characters and stages and encouraging others that they may use all coding provided in their released material, which due to a lack of adequate documentation in early versions of the engine served as examples to how some sctrls functioned.

At the very least, T.E.S.T.P had a good relationship with them, as the only others known to later receive advanced betas were donators for the purchase of a Windows compiler.

Developing Content for the Engine

Before the existence of many development tools available today, Elecbyte provided command-line utilities such as SPRMaker, SNDmaker, PCXClean and pal2act to assist in the development. In addition to the aforementioned programs, M.U.G.E.N was packed along with tutorials and documentation to build M.U.G.E.N content. KFM, the character included in M.U.G.E.N distributions, is well documented and serves as a template for character creators. Coding for MUGEN usually is done over text editors such as notepad. For the graphical aspect of creation, tools that can handle PCX files such as Adobe Photoshop or Paint Shop Pro are used to either process the sprites to be used in the SFF or to generate palettes. AirEditor, also by Elecbyte, facilitated in the animation aspect of creation as well as collision box modifications, though notepad/wordpad can suffice also.

Today, there are more centralized software available that are dedicated to M.U.G.E.N development like MUGEN Editing Ensemble, Fighter Factory, and MUGEN QuickEdit. Although MUGEN Character Maker (MCM) is not as all-encompassing as the previously mentioned programs, it can still build SFF, AIR, and SND files. More recent creators rely on these programs which are actually a compendium of tools. Other tools are standalone programs that are dedicated to one aspect of M.U.G.E.N creation, like with the manipulation of SFF files (M.C.M.) or SND files (SouNDsGood).

With each revision of M.U.G.E.N there have been compatibility problems with changes and additions in state controllers, triggers, and with the latest Linux and Windows distributions, SFF's. Due to Elecbyte's disappearance, compatibility problems arising from new versions are nonexistent. Elecbyte never provided an automated updater, citing the impossibility of such a feat. However, they did provide a detailed change log for each version to facilitate updating to a new version of the engine. In response, a third-party tool called SFFextract was created to extract the pcx files of an SFF and produce a txt file to pipe into sprmaker. SFFextract when used properly is able to assist in modifying an SFF file so later M.U.G.E.N versions could handle.

File Structure

Characters and stages in M.U.G.E.N are modular and flexible. How they are structured is primarily defined by the common convention of tool makers, rather than the internal makeup of M.U.G.E.N itself. Aside from media files (graphics and sound), the files defining a character or stage are mostly left as plain text.

• DEF: Definition file; has various purposes. For characters defines the name, authorname and files associated with the character, while more specific DEF files such as SYSTEM define the outer 'skin' of the engine (commonly called screenpack or motif), and FIGHT defines the HUD (or lifebars) for the actual fights themselves. Note that SYSTEM.DEF and FIGHT.DEF are not absolute names, but those commonly used (and used by the default motif). For stages, the .def file acts as both .def (files associated with the stage) and .air file.
• ACT: Palette file; used with characters to define the character's colors in game. Each character can have up to 12 palettes (one for each attack button, and one for each attack button while holding the Start button). Editable with programs like Paletero, Fighter Factory and ActEdit.
• AI: A file the engine itself writes when the line "ai =" (followed by a filename) is included in the DEF file, and is not covered in the documentation. It was discovered through experimentation. While the engine clearly does read the file it has made (an AI file from a different Mugen version gets dubbed invalid and rewritten with an error message present in the debug text), there's no surefire indication that this file actually augments the character's natural AI when controlled by the CPU, although the growth in size after successive or prolonged usage of a character shows that data is being written. This type of file is the least used among content creators due to both the absence in the documentation and the relative newness of the file type's discovery.
• AIR: Animation file; tells the program how to play back a sequence of sprites to form an animation. The character's collision boxes are also defined here.
• CFG: Configuration file, used solely by the engine. The file, mugen.cfg can be found in the data folder of the engine, and defines the basic functions. Some options are modifiable from M.U.G.E.N itself as Options while some are only modifiable through the file itself.
• CMD: The command file, defines what commands the characters can use. Up to 128 unique attack commands can be defined here. This has led to some minor problems with newer versions of Windows that have started using this filetype for purposes unrelated to the M.U.G.E.N engine. Recent versions of windows reserve this filetype as a format similar to BAT files, leading to some complications, such as email services like Gmail blocking the file type fearing it to be a virus.
• CNS: Character constants file; defines how a character acts and moves in terms of velocity, height, width etc. Also, coding is typically placed in this file instead of/along with ST files.
• FNT: Font file; is constructed from the combination of an 8-bit pcx image and a correlating txt file. The pcx image depicts the characters that would be defined in the txt file from left to right. The txt file would tell where each of the characters begin and end relating to their location in the pcx image. Usable characters may be limited to ASCII's 128, but might be able to be extended to roughly 255 unique characters through the allowed usage of hex codes to define characters in the txt file. M.U.G.E.N does not support characters that are defined by more than a single byte. Although intended to create an alphabet, single-letter stage names allow a workaround for FNT files to display stage previews on the select screen.
• SFF: Sprite file; contains one or more sprites constructed from PCX images at 256 colors. Used for all sprites associated with the different parts of the engine, ranging from characters and stages to the screenpack itself. Pre-Linux versions of M.U.G.E.N allowed for stages to use unpaletted PCX files. While removed from the Linux version on, it was replaced with the option to use PCX files within characters that used a different palette, allowing for further possibilies notably regarding hitsparks and fx.
• SND: Sound file; contains one or more sounds constructed from WAV files, and like SFF, used by all related parts of the engine (characters and screenpack).
• ST: State file; defines character behavior and attacks. Optional, in that commonly coding is used here, but many characters like the default Kung Fu Man put the coding in the CNS file instead. Coding can also be put in the CMD file (as shown with State -1).

Note that with the exception of CFG, none of these file extensions are enforced by the engine, and serve only as the standard set by Elecbyte. However most mugen tools do follow most of these absolutely, notably in regards to SFF and SND.

Reception

Despite its dual status as an engine to make games and a game itself, M.U.G.E.N typically regarded as a heavily customizable game solely by magazines, websites and newcomers to M.U.G.E.N; Eliza Gouger of Kotaku described it as "some crazy mashup game", referring to a video of Godzilla smashing through the first level of Super Mario Bros. Demos of the engine have also made their way into magazines (usually with a mishmash of works from various creators), or by purchasing a compiled game on eBay, a practice heavily frowned upon given the illegality of selling the engine itself and other reasons (see Controversy over Redistribution of M.U.G.E.N Works, below), believing that they're purchasing a commercial game only to find it to be M.U.G.E.N. Those introduced to the engine the first time through compiled games tend to be discouraged to further use it, as these game compilations (a combination of characters, stages and a screenpack) tend to be unmodified for balance and gameplay, giving the image M.U.G.E.N is nothing more than a "jumbled mess".

Users of the engine itself have decried flaws of it. Without CMD optimizing and other tricks to boost the attack frequency, Mugen's AI is very weak compared to commercial fighters, offering not much in terms of competitive gameplay, and raising the engine's difficulty level has little effect on difficulty. To counteract this, character creators have scripted their own workarounds via AI scripts and activation of said scripts within the character's CMD file (the one regarded as most reliable thus far being by creator Winane, who compiled many reliable methods into one working one). Stage interaction and character transformation are two other major items for players that are missing, though workaround methods using a stage's formerly obsolete starting z-axis positions have been used to give stages an 'ID' for player characters to detect, though not without limits. Errors in the documentation have led to issues regarding comprehension of key features, and the placement of required sprites has been cited as tedious. Regardless of these shortcomings, M.U.G.E.N creators have been creating content for years, pushing the engine beyond the application of fighting games. Other game types possible include arcade-style shooters or platform games, such as Bane84's Xtreme Theme Shooter Machine (a game featured in the December 2006 issue of the magazine Hardcore Gamer), KGenjuro's J'Dar II (a vertical shooter akin to Solar Striker), or Falchion22's platformer Castlevania X, a tribute to the game series of the same name. Many legitimate full games also exist and have received praise by websites in the community, such as Bia's SF2NES, the King of Fighters Zillion project, and Babel Sword by Tatsu.

As a game, M.U.G.E.N receives mixed reviews due to the content available for it. Many characters due to poor coding, an emphasis on graphics instead of gameplay, and/or highly overpowering a character leave for a very unbalanced battlefield. Scripted AI to overcome mugen's shortcomings tends to be of one extreme or another, and in most cases tear apart the majority of characters that lack AI. The biggest decry against the game however seems to be the inavailability of some content due to various reasons. Not everyone fully understands the "community ethics" and reasoning behind the community's rules and limitations on hosting of works without permission, and thus become frustrated that they can't get what they would like to play with (some however are aware yet simply choose not to care. See Legality, below). To counteract this some forums run request services to exist for person-to-person content distribution via email or PM, notably the largest service of this sort being Mugen Museum.

However, despite these flaws, some people enjoy M.U.G.E.N. The idea of seeing and playing their favorite characters fighting other characters that they normally wouldn't fight is enjoyable. For example, Homer Simpson vs. Wario or Mario vs. Onslaught Some people have made mini games in M.U.G.E.N like the Duck Hunt level. The object of the Duck Hunt level is, like the Nintendo game, to kill as many ducks as possible. There is one video in which Apocalypse and Onslaught both try to kill as many flying ducks as possible. There are quite a few M.U.G.E.N videos on YouTube as well.

M.U.G.E.N has appeared on television shows more than once, notably seen on G4's "Attack of the Show," as Peter Griffin from Family Guy fought Sakura Kasugano from Street Fighter. The show's hosts believed it was a hack of Marvel vs. Capcom and stated such, but it has been proven to be a video of M.U.G.E.N gameplay [2]. Later it was featured on a VH1 internet countdown.

Legality

File:Babelsword.png

A screenshot from Babel Sword, a completely original game.

The license agreements for usage of M.U.G.E.N from Elecbyte have expired and it appears that a new license agreement will never be granted. Thus, any current distribution of M.U.G.E.N has not been authorized by Elecbyte and is technically illegal. With the license expired on all versions, when running the M.U.G.E.N program, the user is reminded of this through a nag screen. While illegal, some view that the purpose of the executable's nag screen was to encourage adoption of newer iterations of the engine. Evidence of this can be inferred by the brief period of time that a license was made available from the release date of a version of the engine--it was often not long enough to develop an original character from start to finish. However, Elecbyte has never taken any legal action; the company has disappeared without explanation. People chose to continue using M.U.G.E.N, and deprecated versions of it, despite the lack of a new license (the DOS version was still in widespread use when its license had expired at a time when the Linux version's license was still valid). Creations, such as characters and stages, for use with M.U.G.E.N are not a part of Elecbyte's license (provided those creations do not include the executable as well), only the software itself is. It is up to the individual whether or not to violate Elecbyte's license by using M.U.G.E.N. Elecbyte itself has not made a public statement since 2003, when they stated that the project had "hit a snag".

Most characters and stages are of dubious legality as well, as most are made using sprites and sounds ripped from copyrighted games. For this reason, some standing communities enforced a loose "time-release" rule, whereby they do not allow linking to characters made from recent games. Eventually the time-release rule was limited to Neo-Geo games as those could be emulated as soon as a rom was dumped and released. While this has no actual impact on the legality of the materials in question, it served to avoid any legal pressure from the copyright holders, and as a means to keep M.U.G.E.N from 'competing' with commercial games and drawing their ire.

Not all companies have a fanart approach to the engine/game. SNK Playmore responding to an email query asking directly about their material being used in M.U.G.E.N creations that they don't support any usage of intellectual property outside of their company, However this decision was later reversed and they allow M.U.G.E.N works as long as they are for private, non-commercial use or resale. A later email query was sent by former MugenGuild admin Messatsu to clarify the situation further, allowing for the works to be distributed freely over the internet. Capcom was sent a similar email query, the response stating they understand that it is just fan art and as such, are not threatened by it. The response under closer inspection is actually just a re-wording of their stance on fan art websites. It should also be noted however that the subject of M.U.G.E.N has come up on Capcom USA's forums with no hostility shown by Capcom's staff, a response very different to that given to projects like Street Fighter Online to support themselves.

However, French-Bread (known as Watanabe Seisakujo prior to 2003), the creator of the Queen of Heart games, and the co-creators of Melty Blood, have asked that content from their work not be made for the M.U.G.E.N or the game Knuckle Fighter X. During the release of Melty Blood, they requested that sounds and voices from the game itself not to be used with the characters, notably loosening their stance regarding conversions. This limitation was removed in subsequent installments of the game series, however previous other content bans persist, notably in regards to the Queen of Heart series. Since then, French Bread has not expressed objections of conversions from their later games, like Glove on Fight or Ragnarok Battle Offline.

The work material has two categories: the content of the SFF and SND files are copyrighted by the respective owners (like Capcom, SNK, etc); the other files, like CMD, AIR, ST, and CNS are copyrighted by the author of the character or the stage. Elecbyte stated that, "The reason for the open file formats is so that you can share techniques with other developers." Yet there has been a great deal of controversy regarding permission (or lack thereof) between coders.

Controversy over Redistribution of M.U.G.E.N Works

There has been debate over the act of hosting the works of content creators for the engine without consent from them, a practice dubbed "warehousing." Warehouses and content 'megapacks' are generally seen as ideal for new engine users who are able to obtain a lot of usable content quickly with little searching. Arguments have risen against this practice. Since the "warehouse" would host all the content they previously downloaded, the content users are unaware of the original source of the content and possibly miss any patches or updates related to each piece of content. Another issue stems from the fact that many authors gain revenue in one form or another by visitors to their sites, be it by advertising banners on their site or merchandising (such as that sold by Mugen Institute for their original Dragon Claw character.) The use of "warehousing" has the potential to drop the amount of visitors to the author's web site, resulting in a loss of feedback, distribution of updates, or as in the case of Mugen Institute a possible loss of revenue.

There is some controversy on the legality of warehouses. Although most of the authors have not registered copyrights pertaining to the code or graphics used to create the content, much like hosting a videogame FAQ it is considered in violation of the author's copyright unless permission to host is given. The debate ranges from original design by authors as well as derivative works or fan art often taken directly from previously released video game characters. A violation of copyright of the original designs would be where the original author has good standing to legally sue an offending web host if the correct documentation was filed before the release of the content. Typically it is argued that legal action is not sought for the misuse of most M.U.G.E.N creations because the origin of sprites and sounds has been ripped from commercial games even though the program code is crafted from scratch or templates.

The debate over warehousing has been long standing, but several key arguments stand out:

• The argument that the engine itself is freeware due to payment not being required or asked for and the timeout function of the program still leaves it fully functional, and thus covered under freeware laws. In reply, opponents state due to the license agreement obtained by Elecbyte, which in part may still apply, M.U.G.E.N itself is actually shareware, and covered under the laws governing such.
• The argument that when copyrighted characters or sprites such as those owned by Capcom or SNK are used in the works, the works themselves are a violation of copyright and thus any claims are to be argued as null and void. Although Nintendo has released a statement against emulation in all forms, Capcom, SNK and other companies have not shown any ill will towards those creating content for the engine, despite being aware of the practice for several years. However, French Bread previously had a notice on one of their older websites that expressed not to convert material found in their games.
• Some sites host original characters generated by the author themselves (such as those by Reu or Rikard), in which case the characters are still copyright of their authors. The copyright on the code itself is the key factor here, though the claim of copyright has been misinterpreted to cover the sprites or the character concept.

See also

• Fighter Maker

External links

• A windows version (typically called WinMugen) can be downloaded at RouHei's website.
• M.U.G.E.N Fighters Guild Network
• RandomSelect hosts older versions of DOS and Linux mugen.
• Mugen-Infantry has a character database
• MugenBR (Portuguese, has an English speaking section)