Rugal was originally going have the ability to copy any move that he saw. However, the game didn’t have enough memory to execute the idea well enough, so the team settled on giving him Geese Howard's Reppuken and Wolfgang Krauser's Kaiser Wave attacks.

The original members of the England Team were King (Art of Fighting), Billy Kane (Fatal Fury Special), and Big Bear (Fatal Fury 2), since all three were English. However, after the release of Art of Fighting 2, the development team decided to make an all-female team, replacing Billy and Bear with Yuri Sakazaki from Art of Fighting 2 and Mai Shiranui from Fatal Fury 2.

Billy would later become playable in the sequel, while Big Bear would appear much later in The King of Fighters XII as his alter-ego Raiden.

Brian Battler is inspired by the SNK football game Football Frenzy. Early designs of Brian depicted him in more traditional football player fashion, but his final design left him without a helmet and a more "casual" uniform. This was done to make him not look exactly like the character Johnny Maximum in the World Heroes 2.

During the early stages of the game's development, Goro Daimon's design was criticized by designers who were of the opinion that it was just plain loopy for Daimon to fight wearing Japanese geta (wooden clogs). But Goro's creators were adamant and he kept his footwear.

Before the final version of the game, Kyo Kusanagi was originally named Syo Kirishima and had a similar design to Shotaro Kaneda from the Akira manga.

According to Kyo’s designer, his final design was inspired by Jo Yabuki from Ashita no Joe, and Akira Fudo from Devilman.

Heavy D! is inspired by the SNK boxing game Main Event. He was named after the American rap artist of the same name from the rap group Heavy D & The Boyz. However, to avoid any possible copyright issues, they added an exclamation point at the end.

His pet cat, Puu, was also named after one of the developer's cats.

Choi Bounge's original design was changed at the last minute to avoid distinct similarities with horror film character Freddy Krueger from the A Nightmare on Elm Street franchise.

The development team intended for Ralf and Clark to be shirtless, keeping them in line with their appearance in Ikari Warriors. However, the higher-ups ordered them to update their designs to look more modern.

In the original Japanese release, opponents expel blood when hit. This was changed to show small hit markers instead when released overseas.