So this post is a bit of a follow-up to my advice to new Gamemasters. I had made mention about trying different rule systems and that there are some specifically designed to be quick and easy; often referred to as rules-light. There could be a variety of different reasons why someone would use a simplified system. One being they are easy to use and a group is able to start playing fairly quickly or with a minimum of setup. Another reason might be that they tend to be more narrative focused, with success being less dependent on a roll of the dice. Or perhaps people are travelling together and a simplified system makes playing during prolonged downtime possible. Whatever your reason, I thought I would introduce people to one of my favorite rules-lite systems and offer a few suggestions to modify it to make it applicable to other types of TTRPG games. Without further ado … May I present Cthulhu Dark?!

Cthulhu Dark was developed by Graham Walmsley to be used in the Lovecraftian Mythos. (If you’re interested in a short history of its development, you can checkout his blog post on Pelgrane Press’ site.) Given the genre, the Player Characters are investigators, either intentionally or they fall into the story unprepared. Character prep consists of naming your character, creating a brief bio with an occupation and a description, and finally having an idea for their personality. Also as we are dealing with the Mythos, every player also begins with an Insanity of 1 … more on that later. That’s it! Character creation done, no stats, no bonuses. You don’t really even need to write any of it down. So how does anything get done? Grab 3d6. Two should be similar but the 3rd needs to be clearly different from the rest. This is your Insanity Die. When a PC wants to perform an action: roll 1d6 if it is something a normal human can do; roll an additional d6 if it is something related to your PC’s profession; and add your Insanity Die (a final d6) whenever the result could affect your sanity. If it is something beyond a human’s capability, such as casting a spell, then you would only roll your Insanity Die.

The dice pool is not about deciding if you succeed or fail, but how well you succeed. When you roll your dice, whichever has the highest number on it determines how well you did. On a 1, 2, or 3 you are able to succeed at the task but there is some form of disadvantage or complication. The level of complication is determined by the number. A 3 would give something akin to a nuisance, whereas a 1 would be a major complication. I like examples, so … Let’s pretend you’re running away from a group of cultists (trying to go with the Lovecraftian theme for now). Rolling a 1 might mean you get away but as you crash through a door you cut your arm, leaving the cultists with some of your blood allowing them to track you down later; a 2 means that you are able to run and hide, but you also step in a hole wrenching your knee or spraining your ankle; and a 3 means you escaped but knocked over an elderly person in your attempt. Rolling a 4 or 5 gives you a success with some extra benefits; continuing with our example a 4 means you leave no trail for them to follow, whereas a 5 allows you to send the pursuing cultists in the wrong direction. Okay, but what about a 6?!? A 6 is still a success, but it is also when you glimpse into the unknown or the world of the Mythos. You hear the archaic and terrifying words of the cultists as they cast a spell to impede your escape, witness the energy hurdling towards you, and therefore dodge its effects but witness it slam into a bystander who is now petrified in stone. That’s not normal, so you’d roll your Insanity Die.

The Insanity Die is the part of the system most agreeable to modification for the game you are wanting to play. In its original setting of the Lovecraft Mythos, whenever a player rolls a 6 and the result is something that is directly connected with the Mythos, then you make a “check” against your sanity. A sanity check consists of rolling the Insanity Die and if the resulting number is higher than your current Insanity level, you then roleplay how that momentary lapse from the perceived world plays out. And with that change, your Insanity level increases by 1. Also, whenever you add the Insanity Die to your dice pool and it rolls the highest number in your pool (it does not need to be a 6 in this case), you must again make a sanity “check” with the same rules already mentioned. You may also “check” Insanity even when not attempting a task or investigation, such as when you witness something distressing. One final note on Insanity, passing an Insanity check doesn’t mean you’re fine or not bothered by the events you witnessed, only that your player character was able to keep things together for now.

Before I answer the inevitable question, “What? You can’t fail?;” let me say one final thing about rolling your dice pool. If you had included your Insanity Die in your roll, you may reroll the entirety of your dice pool to get a better result. If you had not included your Insanity Die and still wish to reroll, you may do so but the Insanity Die must be included now. One caveat is that no matter if you are rerolling your pool, if your Insanity Die is the highest you still make a sanity “check” before the reroll and make sanity “checks” for any rerolls in which the Insanity Die remains the highest number. As you can imagine, this means that the investigators are on the inevitable road to madness as they slowly come to face the reality of the Mythos. The process can be stymied through “suppressing knowledge.” It can entail burning mythos-related works, interrupting a ritual or even your own party’s investigation into the Mythos (forbidden knowledge is best left unknown or forgotten, which is heavily related to Lovecraft’s original works). The rules pamphlet does mention “destroying yourself” as a means to suppress your PC’s knowledge of the Mythos. In context it does make sense, if one of your eyes is now able to see into the Dreamworld, in a fit of madness it is conceivable to rip it out so you no longer see the images. I do think it important though to mention that introducing ideas of self harm into play should not be taken lightly. The ability to suppress knowledge can only happen, however, when your character reaches an Insanity of 5. Mechanically this is done by making an Insanity “check,” but needing a lower number than your current Insanity level. If successful you subtract 1 from your Insanity level and may continue attempting to suppress knowledge as long as it makes sense in the narrative context. Once an investigator reaches 6 Insanity, they go incurably insane as the player roleplays how this happens in the narrative.

Failure is always an option, but rolling is about how well the player character succeeds … so how does that work? Cthulhu Dark, as designed, is not really about beating the Big Bad End Game monster. I forget who described it as such, but the difference between the creatures in the Lovecraftian Mythos and humanity is comparable between a human and an ant. The terror in this horror reality is humanity is incapable of stopping these entities. If a player character comes across a Shoggoth, a Mi-Go, a Dagon, or any truly-otherworldly creature, they cannot be defeated. Period. The PC’s action may be to fend off a blow or to escape but never to defeat them. If the PC remains to fight, they will fail. The other means of failure is related to the concept of the game as a shared experience and an understanding that it is not a game about “winning,” e.g. defeating the monster. The other players at the table decide when there is a possibility for an attempted task to fail. In this scenario the player calling for the possibility of failure describes what the failure would look like, just as the player of the acting PC describes what they are attempting to do. Once both these realities are offered as possibilities, then the player with the acting PC rolls their dice pool while the challenging player rolls a d6. If the challenging player’s die roll is higher than anything else rolled in the dice pool of the player attempting the task, then the act fails and what the challenger described happens. The only time this cannot be done is if the player character is investigating to learn information that furthers the story; success can be challenged only against actions. In cases of ties when players are rolling in competition, the player character with the higher Insanity level wins unless that too is the same then the players reroll. N.B. The reroll rules still apply. Also when cooperating on a task as a group, each player character has their own dice pool but the highest number of whichever PC’s dice determines the level of success. And again, the reroll and Insanity Die rules are in effect.

How to Modify It

Cthulhu Dark is first, last, and always about Cosmic Horror and the inevitable doom of the player characters. After playing, I’d suggest watching a few videos of Golden Retriever puppies doing what puppies do … you’ll need it. However the mechanics are based on a couple of simple principles. The first being the continual progression of the storyline being played through. And the second is the statistical probabilities associated with levels of success and the uncertainty when another player decides to challenge a success. The concept of levels of success based on the outcome of dice rolling doesn’t really need to be tweaked. You might not need to accidentally tap into the Mythos when rolling a 6, but it can still act as a wildcard factor. The piece that needs to be changed depending on game genre is the Insanity Die. Outside of a horror-themed game perhaps it can be reskinned (yeah, that one was intended) as the health mechanic. The Insanity Die is now the Health Die and is rolled whenever there is the possibility of injury. When rolling a 6 in other situations there could be blow back that causes your PC unanticipated harm. Another possibility is the Insanity Die becomes your Luck Die, which will eventually run out … or maybe its for when you use your superpower or cast a spell or read love poetry to your suitor or use the experimental technology your PC created. My take away point is that the 3rd d6 becomes the mechanic unique to the genre you and your group are playing. After that, character creation and the game’s storyline is now up to your group.

Other One-Page RPG Games

At the start of this post I did provide a link to where you can pick up a PDF-version of the Cthulhu Dark pamphlet for free on Graham Walmsley’s website. A few years ago he also ran a successful Kickstarter campaign to publish a hardcover-version of Cthulhu Dark with expanded information for gamemasters to build their own scenarios, as well as including 4 campaign settings with an adventure in each: 19th-century London, 17th-century Arkham, Modern-Day West Africa in the fictional country of Jaiwo, and futuristic Mumbai. I believe it is now out of print, but a PDF-version of the full ruleset is available via DrivethruRPG. In addition to Cthulhu Dark there are a number of other One-Page RPGs available. What you’ll find below is only a small list of them. In other words a random sample with the addition of Honey Heists just because. I’m including them mainly for convenience and a sampling of differing genres. So I make no claim that they are all winners!

• Honey Heist
• Brianwood
• System Shutdown
• Dead Channel
• CRAM

Give either Cthulhu Dark or some other one-page RPG a try. If nothing else, you may find something you didn’t know you were missing or even the possibility for inspiration to your normal game.