In an early version of the story, Alexia and Alfred Ashford were originally known as Hilda and Hilbert Krueger, respectively.
Jill Valentine was originally intended as the game's protagonist. However, when Hideki Kamiya added the last line to the Resident Evil 2 ending to suggest Leon S. Kennedy and Claire Redfield would go on a quest to fight Umbrella, writer Noboru Sugimura was forced to replace her with Claire. The freedom of the character thus allowed the Resident Evil 3 staff to use Jill.
Rumor has it that Leon was at one point going to be Claire's partner in this game and also die near the end. Capcom quickly realized how bad an idea it would be to kill off such a well-liked character and turned him into the new character named Steve Burnside instead (if true, this would explain why Steve looked so similar to Leon in the original release).