The world of One Shot RPG is filled with monsters. Cosmic horrors have invaded the solar system, threatening all. There’s a mysterious substance, scum, that has the ability to transform individuals into twisted beings. The player characters have decided to deal with the scummed, but their options aren’t black and white.

Adding More Lore

New players shouldn’t have to know a lot of lore to be able to enjoy One Shot RPG. The additional information should be supplementary to the elevator pitch. Important elements should be communicated through gameplay elements and story beats, instead of through walls of text. But, the lore has to be fleshed out first before I can integrate story and gameplay.

Cosmic Horrors

The solar system has been invaded by cosmic horrors, aliens with creepy features that defy biology. They can live in the vacuum of space and have unexplainable abilities. Theorized to originate from Planet X, they have come to our solar system by warping through Pluto. The small ones are the size of elephants, while the large ones are the size of cruise ships. They use the asteroid belt as cover, retreating to it when they aren’t assaulting ships and planets. Those that believe in scum also believe that the cosmic horrors are the end result of the substance’s infection. They believe that using warp technology has completely scummed the creatures into unrecognizable forms. These monsters aren’t what the players fight—they’d be no match—and are best left for the military to take care of.

Cosmic horrors are used to add an overall conflict to the one shot game setting. They are based on Lovecraftian monstrosities and their appearance adds a sense of alien to contrast with the playable humanoid races. The inspiration for including cosmic horrors in the setting comes from a personal place; I tend to draw tentacled beasts, so it was only natural to put them into the setting.


There’s no actual proof that scum exists, instead it’s only been theoretical. The substance is undetectable, yet its effects can be observed. The theory goes that scum is a byproduct of warp technology, that traveling faster than light somehow creates scum as waste. Because Pluto is an active warp gate, it’s releasing a steady stream of scum into the solar system. The substance is making its way to the inhabited planets, and may have already coated everything—nobody knows how much is already present.

Scum has a unique property in that it can twist and corrupt living, sapient organisms. Being exposed to a small amount of scum is harmless. It’s only when it accumulates in large quantities that it poses a threat. Scum is somehow able to understand emotions, intentions, beliefs, and motivations. When a person with extreme drive experiences a life-altering event while exposed to a large amount of scum, the substance reacts, changing them. They become twisted, gain abilities, and will stop at nothing to achieve their goals. The person has become scummed, a monster that’s similar to the large cosmic horrors that plague the solar system.

Scummed individuals are not evil. Instead they were people who believed they were doing the right thing who now have access to destructive abilities that they can barely control. The scum has clouded their judgement and has heightened their drive and emotions. They will stop at nothing to achieve their goals.

Example of a Scummed Individual

Fifteen years ago a parent’s child was almost abducted. Luckily they were paying attention and the child got out of the situation safely. Ever since then, the parent has been on a campaign to raise awareness around the dangers of abduction. They worry for every child’s safety and work tirelessly towards their goal. Now their child has moved out, they’ve become an empty nester, and are coming to terms that they can no longer protect their child. The world is filled with dangerous people, if only they could do something about it. A large amount of scum reacts to this person, twisting them into a monstrous being with new powers.

The scummed individual wants to rid the world of predators, to prevent what has happened to them and their child from happening to any other family. They stalk their neighborhood, looking for anyone they think is displaying suspicious behavior. When their target is chosen, the scummed uses their abilities, in this case the power of suggestion, to lure the victim to their house. The parent has converted their house into a prison, where they use their new physiology to restrain and torture their prey. They’re looking for a confession, to validate their belief that their prisoners are a threat to society. When a victim finally admits to wrongdoing—whether the confession is true or not—the monster exacts “justice”, and disposes the evidence. To the scummed, any person is a potential abductor, so anyone who enters the area is fair game. The parent, whose goal is to rid the world of predators, has become one themselves—scum has done its job.

Justification for Scum

Scum is designed to be the primary source of horror for the sci-fi and horror adventure setting. What are the story implications if your friends and family could turn into a monster at any time? What happens when you have to confront a scummed loved one? What happens if you gain the attention of a scummed and are now its prey? Its abilities are unknown, they could do anything to you. You’re now part of their twisted vision for a better world, and your wellbeing is the last thing they’re thinking of.

As discussed in the requirements for a successful one shot rpg setting, there needs to be personal, smaller scale problems for the players to tackle. Scummed monsters are the answer to that. They provide a threat that the players should stop, yet it isn’t a world-ending disaster if a few scummed monsters aren’t taken care of.

Another goal is that the one shot adventures provide players with morally gray choices, and that the villains aren’t necessarily evil. The scummed parent is doing bad things and must be stopped, but their intentions are pure. They believe they are doing good by ridding the world of predators. How the players tackle the problem of scummed individuals is a major driver of story and gameplay decisions.

Scum Fighters

Players take the role of scum fighters—people who believe in scum and are doing something about it. They view it as their duty to stop (or at least investigate) the scummed threat. Each character has their own unique relationship with scum and their motivations for stopping it. Perhaps they found out about scum when their significant other succumbed to it. Another character’s best friend may have fallen victim to a scummed. A third character may be a scientist, looking to find a way to prove its existence, with the intent of getting rich off its discovery. Regardless of the circumstances these characters have been branded traitors by the military for actively working against their campaign for the warp drive. The common folk view them as insane—scum is only a rumor after all, and its existence can’t be proven. Others even view the characters as heretics or zealots. Does an unprovable force that has the ability to shape life and destiny, that only some groups believe in, sound familiar?

The reason for casting the characters as scum fighters was discussed while developing the elevator pitch. It gives them a hook to go on adventures, grounds them in the story, and gives them a place in the world. Players know what they’re supposed to be doing during each rpg one shot, but how they accomplish the goal of taking down the scummed is up to them.

Dealing With A Scummed Monster

How the players will deal with a scummed monster will be one of the main pillars of the story and gameplay experience. The players could decide that the individual has caused so much damage that they must be put down. This would be the most straightforward, yet cruel, option. The players could decide that the scummed’s actions and methods are doing more good than harm, and leave them to their own devices. That type of story would be interesting if the characters had to work their way out of the monster’s grip first, then reasoned with and got to know the individual. Finally the players could try to “cure” the scummed individual and return them to a less dangerous state.

Curing Scum

How can a scummed be cured? I don’t know the answer yet, and it’s a topic I’ll explore in the next process article. My goal is that curing a scummed should never be the default option. It should have enough balanced benefits and drawbacks that the other options (killing the monster or leaving it be) are also valid decisions. As I’ve said before, every decision in One Shot RPG should have some shades of gray.