This can be anything from Hyperspace in Star Wars, Warp Drive in Star Trek, travel through the Warp in Warhammer 40k or anything else.
I’ve always liked “slow” FTL travel, where going a few light-years still takes a few days or so. I also really like travel through an alternate dimension like in 40k, Event Horizon, Witchspace in Elite Dangerous.
I wanna know your favorite versions, or do you prefer stories that obey the laws of known physics, like the Expanse or Rimworld?
Here’s how I remember it, could be wrong, been a long time. The super advanced entity, the Eschaton, descends from humans in the future. Any FTL travel that would break causality within the Eschaton’s historical light cone is banned; I.e. anything that could interfere with the Eschaton’s development. Human civilizations have causality-safe jump drives that navigate in ways that avoid causality violations within the Eschaton’s historical light cone.