"Do My Dark Thoughts Mean I'm Bad?"
No! Here's What You Need To Know

You might just have strong mechanical curiosity. You might sit down and start thinking about the details of a fantasy kingdom, only to find your mind wandering off to thoughts of how precisely they torture people down in the dungeon. Yikes! Does that make you bad? Does this mean you subconsciously want to torture people? Not at all! It could just mean that you have the kind of brain that is easily captivated by the fine details of how and why things work, even if they are pretty disturbing and squicky. As long as you don't start trying to find justifications for torture, you don't have to worry - you're not evil. You can acknowledge that bad things exist without endorsing or approving of them, let alone engaging in them.

You might be stressed out and feeling trapped. Feeling stressed and trapped tends to put most animals in an agitated and fighty state of mind, and humans are no different in this regard. Agitated and fighty moods easily lead toward violent fantasies and urges. So if you find yourself with thoughts like these, consider what's going on that's got you feeling stressed out and boxed in, and see if there's anything you can do about it. (Focusing on what you can change and do something about, instead of what you can't, is often a good first step.)

You might be experiencing intrusive thoughts. Intrusive thoughts can involve every disturbing act and subject known to mankind, and if they pop up frequently you might start to wonder if that means that you subconsciously like or want this sort of thing. The answer is no. Intrusive thoughts can sort of be described as the brain's "find the most shocking and inappropriate thing you can think of" function gone haywire. Occasionally you might even feel a weird urge to actually do whatever you think of, but it doesn't mean you're actually bad or evil - it might just mean that you desperately crave the rush of adrenaline your brain is convinced that doing this will give you.

You might be depressed. Depression can make it difficult, if not impossible to see the good things about life and humanity as meaningful. Instead, the only thing that your brain registers as important are the negative things. Because of this, you might start to believe that bad things always negate or erase good things, or that humanity's good side is so insignificant compared to its evil side that it deserves to be severely punished or even annihilated. In addition, you might be so desperate to feel something that isn't sadness, existential despair, or self-hatred that the adrenaline rush your brain is sure you'll get from doing something violent seems awfully tempting. In this case, you should talk to a therapist and try to seek treatment, because this doesn't make you a bad person - all it means is that you're suffering a condition that deserves to be treated, not condemned.

If your fears and doubts are causing problems for you, here's what you should do: First of all, don't condemn yourself or beat yourself up. Avoid catastrophic thinking - if you find yourself thinking that you must be a horrible monster because of some unfortunate urge or inappropriate thought, remind yourself that this isn't how things work (because we are defined by our actions, not our thoughts and impulses) and try to move on. Seek therapy and counseling, if at all possible. Search the Internet for coping techniques.

Also, don't engage in emotional self-harm. Emotional self-harm can include trying to get friends or peers to tell you how awful, ugly, or worthless you are, or by visiting websites and communities that make you feel inherently flawed or worthless, or by writing or saying awful things about yourself. (If you think that it's "only just the truth," I can assure you that it's not - you're most likely depressed and suffering from some seriously distorted thinking.)

So there you have it: Having "dark" thoughts does not necessarily mean you're bad, nor that you're doomed to commit some horrific crime. It could just mean that you're a little eccentric, or that you're unwell and need help. In any case, don't panic and don't beat yourself up, and take the best care of yourself that you possibly can.