Welcome to the RADS Roleplaying Game. RADS is a lightweight system of rules for roleplaying as people with radioactive powers in an alternate version of 1979.

Your character is a Rad, a seemingly ordinary person who, through exposure to normally deadly radiation, has developed supernatural powers that confound traditional ideas of cause and effect, letting you reshape a portion of reality to your own ends.

You and your friends characters form a cell in the secretive and subversive resistance organisation called The Free Rads, committed to fighting radiation-born monsters called ‘demons’, as well as the scientists, soldiers and secret agents who create and control them.

Individual games of RADS are called missions. A mission is likely to take around 6-8 hours to complete, and can be split up over the course of multiple sessions of play. Missions are made up of individual scenes, which usually take place across one continuous span of time, in a single location, and have a single overarching goal. A scene tends to take about 15 to 30 minutes to play out.

How do you play RADS?

In RADS, you and a group of friends create the story of characters in a fictional world, determining their feelings, beliefs, decisions and actions.

The world and everything that fills it is created by another player called the Game Master, or GM, who describes what your characters see, hear and feel.

Based on this description, and after asking any clarifying questions of the GM, you’ll decide what your character wants to do.

The GM will then use the rules of the system to decide whether it’s possible, how likely it is to succeed, and then one of three things happens:

RADS uses dice of varying sizes and shapes to determine the outcomes of uncertain events, reflecting the role that myriad tiny unpredictable influences play in the outcome.

Doing things and rolling dice

You roll dice when you attempt to do something which (as determined by the GM):

  1. has a chance to succeed or fail, and
  2. has narratively meaningful consequences for success or failure.

To determine the outcome of this attempt, you roll one or more dice, increase or decrease the result in accordance with any bonuses and penalties, and compare the result to a target score. If your result meets or exceeds the target score, the roll is a success. If the result does not meet or exceed the target score, you fail.

Whenever you are called upon to roll dice, the number and size of dice to be rolled are described using a standard notation system of XdY, where X is the number of dice to be rolled and Y is the size of the dice. For example, you might be asked to roll 2d6, which means you’ll roll two six-sided dice and add the resulting numbers together.

Going undercover

GM: The constable has accepted the forged identity documents marking you as a solicitor. He leaves the room and you are alone with Mr Conington, who looks at you nervously.

Simon (playing Doug Hertfield): I want to find out what he remembers about the demon attack last night.

GM: Okay, how do you plan to do that?

Simon: I’m going to introduce myself, I guess. “Mr Conington, I represent Staples & Masters law firm. We’re here to represent you, if you need it. Can you tell me in your own words what happened last night?

GM: He knows there’s something weird going on, so he’s on edge, but at the same time he’s desperate for a friendly face at this point, so this won’t be too tricky. Roll wits to see how convincing your impression of a solicitor is.

Simon: Okay, I have 2d10 for wits so I should be good. My day job is Bureaucrat, I figure this is kind of that wheelhouse. Will that help?

GM: Sure, add 2 to the result of your roll.

Simon: That’s a 3 and a 5, plus 2, for a total of 10.

GM: He stares at you for a moment, then bursts into tears, saying “Oh thank goodness you’re here! It was horrible! There was this great big… thing…”

Speeds of play

RADS has two speeds of play: scenic time and combat time. For the most part, you’ll be in scenic time. Your Blade acts from minute to minute, responding to challenges as they arise and using your Powers to create powerful supernatural effects that reshape reality. When you attempt to overcome an obstacle during scene time, you roll dice determined by your attributes, modifying the result if you are using the skills and experience gained in your day job.

Combat time is like a slow motion action sequence in a film. Every second is important as combatants engage in furious conflict. During combat time, you take turns to act and try to balance acting quickly, attacking the enemy and defending yourself, choosing dice each round to reflect how your character prioritises these aspects.

Throughout both speeds of play, your character’s most important resource is Energy. Energy lets you turn success into failure, perform logic-defying divine feats and shrug off potentially deadly attacks. Run out, and your character is in trouble.

What do you need to play?

To play RADS you will need this guide, 4d6, 3d8 and 2d10 per player (available from any friendly local gaming store) and a group of friends—4 plus you is the perfect number.

One of your group must be willing to take responsibility for the game and do a bit of extra work to make sure everyone else has fun. If you found this game and nobody else volunteers, congratulations! You’re the GM now. Welcome to the club.

What makes RADS unique?

Different roleplaying systems have different pros and cons, and their mechanics enforce or encourage a certain tone and style of play.

RADS features a simple, tactical and setting-rich ruleset with a moderate level of difficulty. It’s designed to tell dark, gritty stories in the sci-fi/thriller genre—think Stranger Things meets Men in Black. Set in an alternate version of our own world circa 1979, standalone missions play out against the backdrop of the Cold War, where the agents of secret government departments present as much of a challenge as paranormal creatures of pure evil.

Your characters are close to the pinnacle of human capabilities in some areas, but only slightly above average in others; they have powers bestowed by exposure to dangerous radiation, which allow them to bend reality, but only within a highly specific scope and only at the expense of their own vital energy; and while the so-called demons they face are challenging to defeat in combat, the greater obstacles are the secret governmental/military organisations who create these demons for nefarious purposes.

If you play other games or are designing your own RPG, you are encouraged to shamelessly borrow mechanics or narrative concepts from RADS. Remember, every new idea is a remix of everything that came before, novelty matters less than you think, and game mechanics can’t be copyrighted or owned!

Advice for enjoyment

RADS puts the players in the position of morally ambiguous characters with supernatural powers, fighting people warped into unrecognisable monsters by exposure to nuclear radiation. While these transformations are a work of science fiction, there are many horrifying real-world examples of traumatic and deadly experiments conducted on ignorant or unwilling individuals by government-backed agencies. Almost always, these experiments took place at the expense of social outsiders, minorities and disprivileged members of society. Because of the reality-adjacent historical setting of this game, themes of discrimination and social inequality in wider society also have the potential to arise.

Part of the intended appeal of the game is to be able to explore these themes within a safe context, and doing so requires everyone at the table to actively prioritise player safety and support others when they feel unsafe. Below, we outline some things to consider before you start playing.


Some players may find themselves uncomfortable or upset by events which happen or themes which arise during play. If this happens to you, you have permission to pause or stop play in whatever way you wish. If someone else pauses or stops the game, don’t interrogate them about why they feel uncomfortable. Instead, ask if there’s anything you can do to support them and make them feel more comfortable, and accept their responses.

The author encourages and supports the use of the ttrpg safety toolkit, written by Kienna Shaw and Lauren Bryant-Monk.

The tools presented are intended to aid in preventing players from harm, physical or otherwise, before, during and after play. Using these tools is not mandatory, nor does the use of these tools preclude the use of other mechanisms for protecting player safety.

Use your best judgement: if someone expresses discomfort in a way other than by asking you to stop, even if they do so apparently jokingly, or acts in a way that makes you think they might be uncomfortable, it’s better to stop and check than let someone continue to struggle.

While the GM holds a unique degree of power over the narrative and the rules in a way that other players do not, running a game doesn’t mean they are solely accountable for the safety of others at the table, or that they are immune to being made uncomfortable by events that arise during play. It is the equal responsibility of everyone at the table to look after one another and work together to create a safe, enjoyable environment in which to roleplay.


The world of RADS is very similar to the 1970s in our own universe. Across the majority of our planet at that time, racism, sexism, homophobia and other prejudiced views were prevalent and members of disprivileged groups often faced severe discrimination.

When you sit down to play for the first time, your table should discuss how they want to address this in-game. The safest option is to set your game in a world where these issues do not exist and people are not judged based on their ethnicity, sex, neurodiversity, sexuality or gender identity, allowing your table to play diverse characters without worrying about creating additional challenges or rubbing against sore topics.

Some people find roleplaying games to be a powerful lens through which to examine and explore issues of privilege and prejudice, finding enjoyment or catharsis in stories where characters overcome oppression and disprivilege in the course of their adventures. If your table agrees to engage with these topics in this way, ensure that everyone is fully onboard with doing so, and make opportunities for regular check-ins between scenes and at the end of sessions to address any questions or potentially problematic topics that have arisen during play.

If you do decide to embrace period-realistic moral attitudes, be careful when portraying non-player characters who have offensive opinions. While characters with objectionable views may be useful as a foil for underdog protagonists, making such characters overly sympathetic can come across as an endorsement of their views. The author strongly recommends you avoid creating prejudiced player characters.

The author holds the following statements to be morally indisputable:

If you cannot agree with these principles or are not willing to prioritise player safety, this game is not meant for you and you are not allowed to play it.