So I thought I'd get things started here by offering some basic tips for writing murders in these killing games. Mystery is the core of any good Danganronpa story. You've got to make your murders interesting and sensible, or else your whole story falls apart. So, here are ten tips from me. Please feel free to add to this list!

1. Make sure your murder fits your setting. Don't force the setting to conform to the murder. Rather, use the setting to help flesh out the murder and make things more plausible. By limiting yourself, you're forcing both you as a writer and your character to be more inventive with the tools at hand.

2. Don't be afraid to toss out ideas. Often, our first idea is not our best one. We think of the obvious, the easy first, and the more interesting later. The more interesting, the better. The obvious becomes boring.

3. Try to avoid accidental murders. Yes, pathologically speaking, accidental murders make for exciting drama. It's horribly tragic for someone to die by accident. Worse to then be executed for said accident. But they also tend to fall apart, when examined carefully. If you are going to do an accidental murder, make sure there is still some intent on the part of the murderer to accomplish something, and for the murder to be an unintended side effect. For example: scaring someone as a prank, only to give them a heart attack and they die.

4. Write your Closing Argument first. I cannot stress this enough. When you write your Closing Argument first, you set the scene clearly in your head. You have to have your murder fully assembled and then take it apart for presenting to the audience, not the other way around. Allow your protagonist's voice to guide you. And feel free to change it, of course, if some details don't work. That's what rough drafts are for.

5. Complexity is not the same as complicated. This article goes into great depth on the difference between the two. It's from a business perspective, not writing, but it still applies. Keep in mind the difference.

6. Try to avoid making your cases convoluted. You want them to be understandable, both to yourself and to your audience. It's okay to have a lot of details, and to mix them around. Misdirect, yes. Throw in red herrings. But not everything needs to be a Rube Goldberg device with ten different things that could go wrong. Simple is frequently better.

7. Research! If you're going to make a case fascinating, it's best to make sure the medical side is plausible. This is where research comes in. Plausibly depicting injuries and the results of said injuries can not only help add a lot of flavor to your story, it helps make things more interesting. For instance, don't have people knocked out with blows to the head. That's a Hollywood stereotype, not something you can really do without risking permanent injury or worse.

As an example: Let's say character A bashes character B over the head with a wrench. Character A isn't strong enough to kill character B outright. If we follow the Hollywood trope, Character B falls to the floor, with a single splash of blood, little disruption to the crime scene, and is easily finished off. If we go by real life, however, Character B stumbles around, bleeding all over the place, knocking things over and trying to fight back while suffering from dizziness, nausea, and substantial amounts of pain, all while adrenalin keeps them going. The second results in a much more interesting crime scene and it's more plausible to boot.

8. Motives matter. I don't just mean Monokuma's motive-of-the-case. I mean the personal motivation of the killer. Not every killer kills because of what Monokuma offers. The character needs a reason to want to kill the person they do. Their thoughts matter.

For instance: you could have a case where Rarity kills Twilight Sparkle, because Monokuma provides a motive for the successful blackened to become royalty. But Rarity and Twilight are best friends. It's going to take a lot to convince Rarity to kill anyone, especially Twilight, just for her own selfish desire. You have to give a reason. Maybe Twilight has been especially rude to Rarity during this game. Maybe Twilight offers to sacrifice herself because she loves Rarity. Maybe Twilight was already vulnerable and was a victim of convenience. But regardless, unless you give her a damned good reason, Rarity's not killing Twilight, no matter what she's offered.

9. Be careful with memory wipes. Memory wiping is a core aspect of Danganronpa. People always lose their memories or their memories are messed with in one way or another. But you have to be very careful how you do this. The method used needs to make sense in universe. It also needs to have a purpose beyond just making the killing game easier. Sure, it's easier for Rarity to kill Twilight when she forgets Twilight was her friend, but unless there's a good reason to make Rarity forget that, a reason which serves the overall story, it's just a forced contrivance.

10. Have fun. Seriously, have fun with your cases. Throw in silly details. Don't be afraid to inject some comic relief, or some extra confusion, if that's your fancy. But above all else, have fun with it. If you don't have fun with the case, your readers aren't going to like it. Period.

This is solid advice all around. Number 5 is a bit weird one (Not even sure if you are saying if one should be avoided or whatnot), but generally, I've understood a complicated problem has many parts but solvable, while a complex problem with many unknown factors that can't be known for certain.

The 4th one I consider to be the most important tip. While I don't specifically start with a Closing Argument (That is usually the final draft part), what I usually do instead is simply write out what happened from the culprit's perspective and other perspectives as well. Generally speaking, you should have an outline of what happened in the case, who, how, when, why, etc.

Trying to do evidence without having any sort of outline for the case is pretty much putting the cart before the horse

If I had to add something to the list it would be the following.

11. Environment matters. When thinking about cases, you have to think about the environment and how it interacts with the cases. We can take the first case from DR: Trigger Happy. In the first case, the dorms were soundproof, cafeteria and water were off during the nighttime. Naegi's WC door was misaligned, the knife was gotten from the kitchen, the garbage room incinerator can only be accessed with a key that Hifumi had, etc.

Essentially, a well-made environment is a good groundwork for any case. (There is a reason why SDR2 Case 4 and DRV3 Case 4 are so damn popular)

It can be a good idea to take into account where characters would spend time in the environment. Rainbow Dash (human) would very likely spend more time in a gym than in a kitchen. Or Pinkie Pie in the kitchen. Or Twilight in Library.

It's also important to do the set-up for the environment (and other elements). From hints to explanations (correct or incorrect), essentially not all part of the mystery of the case should be introduced all at once, otherwise, it will seem contrived when it gets all dumped at once. There is usually a good reason when characters in the killing games go explore areas that get unlocked.

So when you are making a case, think about how you are going to use the environment and the tools and how they interact with each other and the characters.