Tengen was a video game publisher and developer that was created after the video game crash of 1983-1984 by Atari Games. (Atari Games was formed when Warner Communications sold the consumer side of Atari Inc. to Jack Tramiel, resulting in two companies: Atari Games and Atari Corp.). After Nintendo nearly single-handedly revived the market, Atari Games realized that there was still money to be made in home video games after all. Since Atari Corp. was already involved in the home video game market with the 2600 Jr., 7800, and XEGS consoles, Atari Games chose to create a new brand name to market their games under. They also chose to make games for the market-leading Nintendo Entertainment System rather than introduce a new home console of their own. The new subsidiary was dubbed "Tengen", which in the Japanese game Go refers to the center of the board. (The word "Atari" comes from the same game.)

Tengen unsuccessfully tried to negotiate with Nintendo for a less restrictive license that would allow them to release more than five games per year and that their games would not have to stay NES-exclusive for two years. Nintendo was not interested, so Tengen agreed to their standard license in December of 1987. In 1988, Tengen released their first (and only) three cartridges licensed through Nintendo - RBI Baseball, Pac-Man and Gauntlet. Meanwhile, Tengen secretly worked to bypass Nintendo's lock-out chip called 10NES that gave them control over which games were published for the NES. While numerous manufacturers managed to override this chip by zapping it with a voltage spike, Tengen engineers feared this could potentially damage NES consoles and expose them to unnecessary liability. Instead they chose to reverse engineer the chip and decipher the code required to unlock it. However, the engineers were unable to do so, and the launch date for their first batch of games was rapidly approaching.

In desperation, Tengen turned to the US Copyright Office. Their lawyers contacted the government office to request a copy of the Nintendo lock-out program, claiming they needed it for potential litigation against Nintendo. Once obtained, they used the program to create their own chip that would unlock the NES. When Tengen launched the unlicensed versions of their games, Nintendo immediately sued Tengen for breach of contract. Eventually Tengen was forced to admit its duplicity and pay damages to Nintendo.

Tengen faced another court challenge with Nintendo in 1989 in copyright controversy over Tetris. Tengen lost this suit as well and was forced to recall what was estimated to be hundreds of thousands of unsold cartridges (having sold only about 50,000). (See Tetris for more.) Later on, Tengen received the seal of approval from Sega, and they began to make games for their Game Gear and Genesis. But this wasn't enough to save them. Tengen, depleted by the costly court battles and defeats, faded into the history books by the mid 1990s.

Tengen's unlicensed NES game cartridges do not come in the universally recognizable semi-square grey shape regular Nintendo licensed games come in, but instead are rounded and matte-black, more resembling the original Atari catridges.

External links

• Atari Games Corp. v. Nintendo of America, Inc. (from Harvard's Openlaw site)
• NES Player's overview of Tengen v. Nintendo