Tekken Tag Tournament’s core concept was based on a joke that accidentally got approved 

In his “Harada’s Bar” series on YouTube, Tekken Project director Katsuhiro Harada revealed that the long-running fighting game series’ PlayStation 2 launch title, Tekken Tag Tournament, actually started as an off-the-cuff gag he made in a meeting in response to sudden demands from upper management.   

“Tag sold extremely well, even though we came up with the concept in just 5 minutes.” Harada divulges. He goes on to explain that the successful fighter-swapping take on Tekken was born out of the ashes of the first version of Tekken 4, which would have been a PC game with a completely different concept to any entry in the fighting game series so far.  

“All of a sudden, the bosses told us that the (first) Tekken 4 project got cancelled.” Harada recounts. He then recalls management telling the Tekken team, much to their surprise, that “Since sales are not doing well, we need to release a new game within 6 months.” The game had to be similar to the series’ previous game, Tekken 3 (1997), but not the same. 

Harada proposed a tag game where players could switch between two fighters. “Due to the memory capacity, we couldn’t have 4 characters on the screen, only 2,” he explains. In Tekken Tag Tournament, players can press the shoulder buttons on the controller to switch characters. If both players happen to perform a tag at the same time, this results in an amusing second or so in which there are no fighters on the screen.  

As Harada explains it, he had just proposed “The first fighting game in the world where there’s no-one on-screen for a moment… It was a joke, so my seniors in the Tekken team burst out laughing.” To his surprise, the bosses liked the idea, and the team got to work on Tekken Tag Tournament, which hit arcades in 1999. As an early PS2 title, it was well-received and quickly sold 400,000 copies in the first four days after release (Source: Edge Magazine Issue 94, page 74). Going on to shift well over 2 million units during the PS2 era, Tekken Tag Tournament spawned both a sequel (Tekken Tag Tournament 2) and a PS3 remaster. Not bad for a game that was proposed as a joke.