The ‘Scenariogram’ is a series of tables, Keeper aids and sheets in the Japanese Call of Cthulhu modern-day sourcebook, Cthulhu 2020. Its main use is to create the bones of a scenario using random tables, with 3 main tables and 9 subtables. The main tables are; Scenario Pattern – determining the main goal or structure of the scenario; Mystery Origin – what drives or starts the scenario; and the Truth of the Incident – what is actually behind the scenario’s conflict. The results of these tables can lead into one or more of the subtables, which cover People, Locations, Monsters, Artifacts, etc.

As I don’t have the time to write a full review, let’s try rolling up a scenario.

Table 1 – Scenario Pattern (1D6)

Roll – 4

Result: ‘tracking/protecting a person – The investigators find a missing person. Alternatively, they must protect a person from a creature/threat.’

Okay, simple enough. Let’s go with finding a missing person. Very typical scenario start. And let’s find out who that person is to start with:

Subtable – People (D36*) *roll 2 D6, using the results like a D100, with one die as the ‘tens. unit and the second as the ‘ones’ unit, making for 36 different results. Very bizarre roll…

Roll – 63

Result: ‘Mysterious person – a person who claims to have come from ‘beyond the gate’’

Increasingly weird, and requires us to roll on the ‘beyond the gate’ table…

Subtable – Beyond the gate (D36)

Roll – 36

Result: ‘Contaminated underground world – beneath Machu Pichu’

Okay, now things have gone off the rails a bit. The investigators need to search for a missing person who is supposedly from a realm beneath Machu Pichu. Let’s move on to table 2 before trying to figure out where the hell to go with this.

Table 2 – Mystery Origin (D36)

Roll – 42

Result: ‘The investigators receive a mysterious message – it’s a letter from the past or future.’

Even weirder. Let’s say it’s a message from the future. To find a missing person… who’s from a disease-ridden world under Machu Pichu… alright, sure, let’s see if the last table gives us something to work with.

Table 3 – Truth of the Incident (D36)

Roll – 64

Result: ‘Servitor race conspiracy – ghouls are trying to increase their hunting grounds in order to survive’

Well, that’s something. Ghouls are looking for a new hunting ground, and how does that relate to our missing person? And why are the investigators getting a message from the future? And how does an underground world, a sickened world at that, beneath Machu Pichu factor into this?

Okay, let’s play with this. The ghouls are looking for a new hunting ground – how about the new grounds are literally underground – the Machu Pichu underworld. The underworld is ‘contaminated’ in the future due to the ghoul invasion. In the present day (this book is for modern day, but let’s say this is a 1920s classic scenario), the underworld is still unblemished, both by the ghouls and modern human civilisation. The message is magically sent from the future by a survivor of this underworld – maybe they’re a civilisation of humans that have always lived under Machu Pichu, or they could be a different species related to humans, like the Deep Ones. The letter sender wants the investigators to find someone that could stop the ghouls’ invasion – maybe this missing person is someone the underworld that left to explore the human world, and in the process tipped the ghouls off to the presence of said underworld. The letter writer wants the investigators to find the missing person before the ghouls do, and send them back to their own world to seal it against the terrors of the outside world, which happens to include not only ghouls, but the temptations of human civilisation.

Why didn’t the survivor send the message to the missing person directly? Or to themselves? Why the investigators? Uh… magic? Who knows, who cares, this is a weird scenario seed, but it could be kind of fun. I could see it being split into three acts:

1) traditional investigative section trying to find the missing person 2) trying to convince the person to return to Machu Pichu 3) helping them escape wherever they are before the ghouls find them.

Maybe have the person be someone close to the investigators, a friend or coworker, explaining a bit more why the message arrive with them. This could also inject some SAN rolls when the investigators discover their acquaintance isn’t fully human. If this was worked into an ongoing campaign, it could be a neat twist to throw onto a reoccurring NPC, with the investigators not only learning someone who’s assisted them up until now is not only not human, but that they also need to convince this NPC to leave, potentially forever. Or they could decide the NPC is more useful to them and just doom the NPC’s home to the ghoul invasion.

And that’s the fun of the Scenariogram. A handful of rolls can quickly spiral into a bizarre scenario seed. Would this thing I jut laid out be usable as-is? Probably not, but it gives something to work with and chew over. The actual tables only take up four pages, but I could see this idea being expanded to make for a full supplement about procedurally generated scenarios at some point, assuming it doesn’t already exist somewhere. An idea for another day.

Before you go, maybe you would be interested in some of the below reviews or replays?
MJRRPG scenarios, Chaosium-released scenarios, Miskatonic Repository scenarios, Japanese scenarios