9. Too Similar To Diablo - Fallout
Fallout didn't start out as the post-apocalyptic role-player we're all familiar with today. Initially, it was a game engine based on the table-top playing system, GURPS.
While head producer, Tim Cain, worked on the project, he hit some major snags. After Interplay attained the licensing rights for two Dungeons & Dragons franchises, it looked like GURPS was finished. Because D&D is the pinnacle of tabletop games, it was more sensible for the company to focus all their energy on that, rather than a lesser-known IP. However, Cain had faith in GURPS and so, refused to back down.
But the problems didn't stop there. Around this time, Blizzard released Diablo, cornering the RPG market on PC almost overnight. Interplay immediately terminated the licensing for GURPS, believing the inferior role-player had no chance of competing.
Rather than going quietly into the night, Cain reworked his entire game into what became known as Fallout. In order to do this, he and his co-designer, Christopher Taylor, had to redesign and recode everything... in one week.
Even though Fallout didn't sell as well as Diablo, it was recognised for its potential, allowing it to spawn many sequels and spin-offs.