After watching the movie Chronicle, I decided to design a set of rules for how psychokinesis (or PK) works. Essentially, it functions like additional limbs, and can be roughly as precise as a human hand. However, it can also deal massive damage. Hitting someone with PK often causes internal bleeding as the force puts pressure on the organs. PK can also be used to create a shield of force. It grows stronger with use, but can be exhausted. PK can only be effectively used on things the user can directly see. If two PK users fought, the shielder would easily deflect a simple blast (reflecting the force onto the surrounding area like a bomb). Excessive use causes bleeding from the tear ducts.
Does this look good? Is it interesting or unique? Just asking for your thoughts, basically. Sorry, I should’ve been more clear.
What kind of story is this? Because I'd say the main question with how you design powers is what the overall feel will be and how that works with your larger story. And if you're not sure what genre you're in it may actually help you decide to think about this. If you are doing traditional epic/adventure fantasy, it's good to have some range in powers usually because this genre tends to have a lot of the interest in the diversity of different fantasy elements in worldbuilding. The nature of the fantasy world also often tends to be important for the plot so you likely want to have a significant amount of rules on its mechanics or a sense of spirituality to it, so the characters can then explore that. The more magical you want it to feel, the more you probably want to leave some questions open to make it feel more supernatural. If your doing horror or dark fantasy, you'll generally want powers to be mysterious and threatening. You probably want relatively few clear rules to help maintain the suspense and intrigue. If it's horror sci-fi, you'll want to explain some of the key elements so that the scientific basis for it can be established and explored, but I would leave some notable questions unanswered. You may want to make powers difficult to control, such that main characters can't easily access them or they're are dangerous risks when they do so. If it's a hard sci-fi, you'll obviously be including a bunch of specific detail, and the key question is whether it all actually makes sense and is plausible. This genre is usually more about detail than splashy concepts because there's more reason to do it this way compared to soft sci-fi. Hard sci-fi fans are often big nerds so feel free to go all out, Dune wouldn't be any popular otherwise . Just don't go any further than the story actually benefits from. For soft sci-fi, you're often going to want to stretch believability a little for the sake of a cool concept to explore. Don't feel obligated to worry about believability and detail anymore than you want to, but you should ask what exactly is supposed to be the most interesting parts of your story and how much believability and detail is relevant. Alternatively, you might be doing soft sci-fi over hard simply because you don't want to spend too much on the sci-fi worldbuilding all together and its more of a good setting for a more character or political oriented story. In which case, don't be unnecessarily ambitious, not everything needs to be super interesting.
I would call the setting 'hard', but the actual power has no real explanation. It's known that the spinal fluid and cerebral fluids of PK users behave like a ferrofluid, but that doesn't actually help to explain *why* the character can do this. It's a bit like the SCP universe, where physically impossible things are analyzed with no real results. The story's more along the lines of horror, but hard science fiction elements are definitely involved.
You are the writer. If this is in your head to do, then start it and see if it works. I think it sounds cool. Kinda gross but cool. I've done the kinesis route but mine wasn't as defense/offense. I've had in the back of my mind if they were ever going to do that but I'm not sure that I, as the writer, could pull it off. Perhaps I should do what you did and develop "rules". Hmm.
