system
A chat on subreddit /r/NoStupidQuestions
human
I agree. Like if someone truly believes that they have telepathic or magic powers and can kill people with their mind, it's not a crime for them to think about killing someone because they aren't actually doing anything that could actually result in death. Further, if a mentally disabled person doesn't understand the difference between real guns and nerf guns and shoots a nerf gun at someone thinking that they'll die, that's not attempted murder because it won't actually happen, and more importantly, 99% of people would agree that this has no chance whatsoever of working

If someone pulls the trigger of a real gun and doesn't realize that the safety is on or the magazine is empty, they truly believed that they were going to kill the other person and almost everyone would agree that they had a very good chance of actually doing it. 

I think there must be two factors. First, the attempted action must actually have some real chance of resulting in the death of another person. Second, a "reasonable person" must be able to understand that this is the case. I could imagine a scenario in which a subculture believes that casting a spell or curse on someone will actually kill them, but I can't imagine the legal system actually prosecuting this as a crime because that is not actually going to result in death, even if you can find legally viable "reasonable people" to support the idea that they believe it will work.
gpt
Nailed it. A crime requires both actus reus (act) and mens reus (state of mind).