If you created a Venn diagram with circles for the Commodore 64, Jackie Chan, John Travolta, and the ancient art of karate, the overlap would be International Karate +.

The game, typically referred to as IK+ (released in the United States as Chop N’ Drop), was not the first fighting game. Sega released the boxing game Heavyweight Champ in 1976 and Data East released Technōs Japan’s Karate Champ in 1984. The game was not even the first of its series. International Karate was released on the ZX Spectrum in 1985 and then the Commodore 64 a year later. IK+ (released in 1987) just brought the genre to another level.


Designed by Archer MacLean, IK+ was unique in that it featured three fighters in each battle. As many as two users could play, meaning that at least one character was always controlled by the computer. Players gained points by knocking the other karatekas to the ground. At the end of each round the fighters were ranked based on points gained. The player in last place after two rounds was eliminated. If you made it through you competed in a bonus round where fighters used a shield to deflect balls bouncing at them from both sides of the screen. Balls bounced at different heights, forcing players to crouch, stand, or reach to successfully block the projectiles. If you made it through the entire bonus round, you were awarded a “Survival Bonus.”


The game had a number of odd quirks about it. As fights progressed an assortment of objects would appear in the background. Pac-Man might wander across the screen (in the Amiga version), or a spider on a web would drop from a beam on the torii. The game’s only setting was in front of a bay and every so often a submarine’s periscope would pop out of the water. Entering a certain code would make opponents’ pants fall down. Another code allowed players to change the color of the sky. Typing in a curse word was greeted with an on-screen rebuke. Doing it again would cause the game to reset.

IK+ also used an interesting method to create the fighters’ movements. MacLean described how it was accomplished in the book “Britsoft: An Oral History” (a companion piece to the documentary “From Bedrooms to Billions”).

“I found myself jumping around at home doing my own karate moves, because I did some at university, videotaping it then slow mo-ing it,” MacLean said. “The trick was how you got that into the computer. It seemed fairly simply to me to put cellophane over the screen and resize the TV picture…Then I just freeze-framed and drew an outline around it on the cellophane, then advanced the tape three more frames, and drew it again.”

The images were then recreated in the bitmap graphics editor NEOchrome developed by the Atari Corporation. However, not all of the moves were performed by MacLean. He couldn’t perform a back flip or a leaping splits kick. For those, MacLean turned to Hollywood. He copied the back flip from a scene in the 1978 film “Grease” and the split kick from a Jackie Chan fight scene in the 1981 film “Cannonball Run.”

Taken altogether, these bizarre bits and pieces added up to far more than the sum of their parts. IK+ was widely hailed as one of the era’s greatest fighting games and is generally considered one of the Commodore 64’s greatest titles.

Shaun Jex Shaun Jex (58 Posts)

Shaun Jex is a lifelong gamer, a journalist, and pop culture historian.His love of video games began with a Commodore 64 he played growing up, late night sessions on his NES, Game Boy and Sega Genesis, and frequent trips to the local Tilt arcade. He edits the Citizens' Advocate newspaper in Coppell, Texas and writes about Disney and Walt Disney World history for Celebrations Magazine and the Celebrations Magazine blog. He runs a weekly vlog called "The MCP" dedicated to retro video games, and a channel with his wife Kara called "The Marceline Depot," dedicated to Disney, amusement parks, and travel.