Bootleg games and not-so-subtle knockoffs are usually frowned upon in the gaming industry. They either get shunned by fans for lacking originality or incur legal action from companies fearing competition. But in some cases, bootlegs and clones have propelled the success of the games they imitate.
4Shin Megami Tensei
The creation of the monster-taming genre—which encompasses any game centered around capturing and battling a wide variety of collectible creatures—is often credited to Nintendo’sPokémon RedandBlue. However, the immensely popular genre debuted years earlier with the start of theShinMegami Tenseifranchise—also known simply asMegami Tensei.
The first game to feature a prominent monster-catching mechanic was the 1987 Famicom version ofDigital Devil Story: Megami Tensei—the first game in theMegami Tenseiseries.Digital Devil Storyis a traditionalturn-baseddungeon crawler in which you’ll encounter an assortment of demonic foes. Rather than having a stable cast of party members, the game only provides you with two playable human characters. The rest of your party will have to be recruited during battles by negotiating with enemies, which involves offering items or cash in exchange for their alliance. You can also acquire demons by visiting cathedrals scattered throughout the game world, where you can fuse your demons to create new monsters.

LaterShin Megami Tenseigames feature expanded versions of the negotiation mechanic, while some spin-offs replace it with alternative ways of capturing demons.Persona 3allows you to acquire monsters by completing a mini-game after every battle, andSoul Hackers 2requires you to complete optional quests to recruit certain demons.
Nintendo reused this monster-taming idea for itsPokémonseries, yet it quickly overtookShin Megami Tenseias the face of the monster-taming genre. Other monster-taming games have tried to rivalPokémonby replicating its family-friendly appeal. Even newer games likeCassette BeastsandPalworldstill try to emulate the casual gameplay and colorful designs popularized byPokémon.

Pokémonhas undoubtedly outperformed its original inspiration, but its success has also givenShin Megami Tenseian advantage over its competition. Whereas other monster-taming games are designed for younger players and casual audiences,Shin Megami Tenseihas set itself apart as the definitive M-rated alternative toPokémon.
Shin Megami Tenseiis notorious for its apocalyptic stories, mature subject matter, andbrutally unforgiving difficulty. The series delivers the challenging gameplay and darker storytelling that many olderPokémonfans have wanted for years, while also appealing to any fans of hardcoreturn-based RPGs. The comparisons betweenShin Megami TenseiandPokémonhave never fully died down—and probably never will—but that’s only continued to benefit the series, as proven by the recent successes ofShin Megami Tensei VandPersona 3: Reload.

3Puyo Puyo
Even if you’ve never heard of Sega’sPuyo Puyoseries, you’ve probably seen at least one of its many clones.Puyo Puyois a falling-block puzzle game—similar toTetris—in which you position falling blobs on a narrow grid, and score points by connecting four blobs of the same color. WhilePuyo Puyodoes share many similarities withColumns—anotherSega-developed series—its faster gameplay and vibrant anime aesthetic give the series its own distinctive personality.
Many earlyPuyo Puyogames wereexclusively released in Japan, and the few entries that did receive an international release were often rebranded with recognizable franchises. The Sega Genesis version ofPuyo Puyowas released asDr. Robotnik’s Mean Bean Machine, which swapped thePuyo Puyocast with characters from theAdventures of Sonic the Hedgehoganimated series. Similarly,Kirby’s Avalanchefor the Super Nintendo Entertainment System replacedPuyo Puyo’s visuals with characters and music from theKirbyseries. Even whenPuyo Puyowasn’t being redressed with popular franchises, publishers were still re-releasing the game under different titles likeQwirks.

The abundance ofPuyo Puyogames inspired a flood ofclones from other developers. Some clones were based off of other recognizable properties, such asTimon & Pumbaa’s Jungle Games(based offThe Lion King) andPuzzle Arena Toshinden(a spinoff ofBattle Arena Toshinden).
Sega later reusedPuyo Puyo’s gameplay to createBaku Baku—another arcade game with nearly identical gameplay—which then received its own knockoffs, with the most notable being Capcom’sSuper Puzzle Fighter II Turbo. Trying to keep track of all thesePuyo Puyoknockoffs became very complicated, to say the least.

Although they were meant to replacePuyo Puyofor international audiences, the rebrandedPuyo Puyogames still helped popularize the series outside of Japan. Many fans who grew up playingDr. Robotnik’s Mean Bean Machine,Kirby’s Avalanche, or similar imitations eventually found the same nostalgic fun in the officialPuyo Puyogames. Without the success of its many clones—both official and unofficial—there’s a good chancePuyo Puyowould never have had the same worldwide success as it does today.
2The Sumerian Game
Unless you have an interest inlost media, you’ve probably never heard ofThe Sumerian Game. Unlike the other games on this list,The Sumerian Gamewas never released in stores. It was developed as part of a collaborative study between IBM and New York State’s Board of Cooperative Educational Studies (BOCES), which examined the potential benefits of using computer games for educational purposes.
The Sumerian Gamewas meant to teach basic economic concepts by tasking players with the difficult goal of managing the ancient city of Lagash across multiple decades. This involved maintaining Lagash’s food supply, managing its workers, and expanding the city. While records from the study provide some details aboutThe SumerianGame, the game itself was never made publicly available. After being used for studies in 1964 and 1968,The Sumerian Gameand most of its original assets seemingly vanished.

Not long after,The Sumerian Gamewas unofficially revived by developer Doug Dyment, who heard someone describe the game while attending a talk at the University of Alberta. Using this description as his sole reference, Dyment developed a heavily simplified version of the original game in 1968 titledKing of Sumeriafor the FOCAL programming language.
In 1971, an updated port ofKing of Sumeria—titledHamurabi—was developed by David H. Ahl in theBASIC programming language. The game’s code was later included in his 1973 book101 BASIC Computer Gamesand the 1978 bookBASIC Computer Games.Hamurabiwas the way that most people experiencedKing of Sumeriaand inspired the creation of many similar strategy games. Some of these were straightforward knockoffs ofHamurabi, while others expanded Ahl’s version with new features. TheseHamurabiclones eventually evolved into the city-builder genre, paving the way for other influential titles likeSim CityandSid Meier’s Civilization.

It’s because ofHamurabi’s popularity thatThe Sumerian Gameis still remembered today. Fans and video game historians tracedHamurabi’s history back to Dyment’sKing of Sumeriaand eventually rediscovered their shared connection toThe Sumerian Game.
Since then, there have been numerous projects dedicated to restoringThe Sumerian Gamein its entirety, including arecent remakebased on recovered documents from the game’s development. WithoutKing of Sumeria,Hamurabi, and the countless clones that followed,The Sumerian Gamewould have been a forgotten footnote in gaming history.
1The King of Fighters
The King of Fightershas an extremely unusual history. In the United States and most parts of Europe,KOFand its developer—SNK—are still relatively niche compared to other prominent franchises likeStreet FighterandMortal Kombat. YetKOFis a global sensation, often considered just as important—if not moreso—to fighting game communities around the globe.
The series is especially notable for its popularity in Latin America, Mexico, and China, with many of its top professional players hailing from these regions. Few video game franchises have a reputation that’s as unevenly spread asThe King of Fighters, but that’s a result of the unique conditions that shaped the series' success.
Throughout the 90s, when arcades were still booming in the U.S. and Japan, SNK released its arcade games on the Neo Geo MVS (multi-video system) arcade board—not to be confused with theNeo Geo home console. Unlike other arcade boards of the era, the Neo Geo MVS included six cartridge slots for running games.
This not only meant SNK’sarcade cabinetscould support multiple games at once, but also allowed cabinet owners to swap out old games for new releases. At the time,KOFgames were still being released on an annual basis, so the cartridge format provided an affordable way for arcade owners to keep up with SNK’s constant output.
Possibly the most important aspect of the Neo Geo MVS was its low import costs. Whereas arcades were simultaneously profitable and affordable in the United States and Japan, the arcade industry in many other countries was hampered byhigh tariffs. Acquiring popular arcade cabinets from acclaimed fighting game developers like Capcom or Midway was too expensive for many arcade owners in these territories. By comparison, the low price and long-term value of the Neo Geo MVS made it far more accessible for overseas arcade owners, allowing SNK to dominate the arcade industry in these countries.
The Neo Geo MVS’s low price wasn’t the only reason it became popular in overseas arcades. Besides being affordable, the Neo Geo MVS was also infamously easy to bootleg. Since SNK was using the same exact hardware to support all of its arcade games, bootleggers quickly learned to reproduce the Neo Geo MVS cabinets and distribute them at an even lower cost.
Additionally, the cartridge-based format of the Neo Geo MVS also allowed third-party developers to produce bootlegged reproductions and unlicensed games for these cabinets, including theinfamously unbalancedKOF 2002 Magic Plus II.
Despite the rampant piracy affecting SNK’s releases, these bootlegs didn’t take away business from the company. If anything, they boosted the popularity of SNK’s franchises worldwide.
In Mexico and Latin America,KOFcabinets greatly outnumbered otherfighting games in arcades, placing them at the center of fighting game communities across the globe. Even after SNK discontinued its Neo Geo MVS arcade boards,The King of Fighterscontinues to boast a massive global following and is still a prominent fixture in arcades around the world.
The modern video game industry is filled withpetty lawsuitsandpointless antagonism against unofficial projects, but these games prove that these projects can be beneficial for gaming franchises. Whether they bring more attention to an underrated series or revitalizeforgotten franchises, clones and bootlegs can be surprisingly effective at boosting the recognition of lesser-known games.