Clones are usually games heavily inspired by other games. It’s when you watch a game trailer or play a game and go ‘Hey this reminds me a lot of, BioShock’, Usually you see games springing up that are similar in theme and gameplay to the hottest new title of a particular genre. Call of Duty, Mine Craft, Age of Empires, and PUBG all have a tone of clones, they’re all very popular games. So if The Sims is one of the most popular games of all time then why aren’t there any Sims clones?
‘The Sims’ is a life Simulator, where you create a character, give them personality traits, life goals, find them a job and help them fall in love. Basically, all the things you should be doing for yourself, but instead you’re on your computer playing ‘The Sims’. The game has a lot of sequels and expansion packs too, I’ve played most of the major ones.
I think the designer, Will Wright(Game Design God) didn’t really think about how the game would have to fit in any particular genre, or that the game would even be as successful as it was, so a completely opposite approach to how a clone would be made. He describes his games to be more like toys that produce unique outcomes that emerge from the player's creativity. Stemming for the many possibilities of this game comes the possible expansion packs which the game developers themselves can produce better than any other team trying to make a clone.
Elements of the Sims like the Character customizer and Architecture tools have been used in other games quite well. On rare occasion, a clone turns out to be better than the original, when the clone improves the game mechanics in a significant way. But I think it would not be easy to make a clone of the sims that are not very specific, like the sims-like dating simulator or the sims-like college simulator.
‘The Sims’ is the blueprint, not a variation.