I had a hard time figuring out exactly how to word this question so I'm going to explain a bit.
I'm thinking of an idea for a videogame where the game mechanics are heavily focused on the logistics and interconnections of technology, so it would be fairly "hard" sci-fi, and near future tech at that. However, I want to set it in a rather fantastical world with big monsters and other unrealistic elements. So it leaves me torn on where to use the fantasy brush when designing things. I'd like to let the game mechanics lead the story as much as possible, while allowing for concessions to fantasy to merge them.
The details of my game world aren't important, but to demonstrate the logic behind this question, I'm basically thinking like this:
I want to focus on the logistics of moving supplies, so I can't have teleportation tech. I want to have lasers and force fields, so I need some kind of fantastical power source. But if I have a fantastical power source, that will make it seem ridiculous if there are any combustion engines...
So to take a different approach to deciding what technology to include in a world like this I'm trying to think of the typical sci-fi technologies and the implications of each, to see what gives me the most room to play around and build on while still having the world "feel" realistic and raise minimal questions requiring technobabble answers.
The best comparison I can think of is Battlestar Galactica. In the reboot, the ships have countless nuclear missiles, hyperdrive capability, and other magic space stuff. But the story revolves entirely around how the ship has no networked computers, how the chain of command works, how the engines break down and need replacement parts they can't manufacture, and so on. While for comparison, every time I watch any Star Trek, I'm constantly thinking "you can literally make food out of thin air, this should not be a problem".
Obviously there are a hundred ways to retroactively explain why teleporters or replicators can't solve the problem of a particular episode, but my goal is to avoid raising those questions in the first place, so those two technologies don't work. Technology that reduces to "A power source, but bigger" raises fewer questions. A hyperdrive can be reduced to "we discovered a way to make engines, but better" without raising a ton of questions about how you feed the population.