The Lazy Man's Guide to Constructing a Call of Cthulhu Adventure

By Sandy Petersen, author of Call of Cthulhu

I have decided to show how I create CoC adventures as I think it would be useful to Keepers everywhere. To do so, I've simply created a scenario here, and written down the thought processes involved so that you can see what I am doing at each step along the way. The way it's presented is unconventional, quite different from the normal scenario write-up, but I think it is clear and straightforward, and should be an excellent teaching mechanism for new Keepers, as well as a resource for experienced Keepers. I have also explained at various points how I solve common problems that arise during a CoC adventure.

Step One - The Situation
First, figure out an interesting situation that would be fun to get the players involved with. The easiest way to do this is to pick out a scene, or even an entire plotline, from a film or story you like. Don't worry if it's well-known - by the time we're done, your players won't recognize it. Any film or story will do - whether good or bad. To show how it's done, and to make the situation as hard as possible for myself, I went to a cult horror film site, and picked the 45th film (because I'm 45 years old). It turned out to be Devil Times Five, an incredibly bad exploitation film I've never seen. The plot synopsis was "Five teens escape from an insane asylum and take over a mountain resort." So ... from this I will create a scenario. Watch and follow along to see how you could adapt these methods for your own adventure. Of course, you should have an easier time than I, because you won't pick your plot randomly.

Right off the bat, I don't want to use mere teenagers as the villains. This is a Cthulhu story, so let's make them cultists. The escaped lunatic idea is cool, so let's not have ALL the villains be cultists - just one. If we make it an asylum for the criminally insane, and say the other four escapees are escaped inmates that the cultist recruited, we start getting what looks like a fun scenario - being held hostage by a group of homicidally insane bad guys should make the adventure plenty scary. Where shall we have it happen? If I was doing this scenario for an American audience, I'd place it in the Rocky Mountains. Since most of my readers will probably be Europeans, let's put it in the Austrian Alps. Let's move on.

Step Two - The Plot

Look at your basic situation and try to see how it can be developed into a story. What is the bad guy trying to do? Are there other important characters? If the plot unfolded without player-character interference, what would happen? To help do this, you can use some simple steps.

Substep Two/A - Who are Available as Victims?
Most Call of Cthulhu investigations have a moderate-to-high death rate. Frankly, you need to provide bystanders, villains, or allies to be killed in the stead of the player-characters. This is no problem in our scenario - we can have as many people as we want in our "mountain resort" to be terrorized or killed by the bad guys.

Substep Two/B - How are the Players Going to Get Involved?

Obviously necessary, but often non-trivial. Fortunately in this particular scenario, the method is obvious - have the player-characters be guests at the resort so they are taken hostage with the rest. They have no choice, now.

Substep Two/C - How can the Plot be Prolonged?

Many possible adventures are not suitable for Call of Cthulhu because they wouldn't last long enough for a good game. More importantly, we need to have excuses to delay the villain's plot to give the player-characters time to figure out what is going on and thwart it. In our particular situation, why wouldn't our pack of madmen simply murder all the people at the resort in creative ways and move on? Since we've made one of them a cultist, one logical answer is that he is here to DO something. After all, why come to the mountains in the first place? Perhaps it's not coincidence. After a little thought, we conclude that the bad guy is planning to hold a ritual on the mountaintop, and he needs to keep (some of) the people in the resort alive until the time for the ritual.

Substep Two/D - Why Don't the Authorities Intervene?

This is not a problem in every adventure. Often, in fact, the authorities CAN'T intervene because the bad guys haven't done an obvious crime, or because the (the authorities) are hunting the good guys, or because it would be pointless. In this case however, a hostage crisis could bring out the SWAT team and end the scenario way too fast, so we need to keep them at bay, at least until the climactic ending sequence. The best way to keep the authorities out of action is to cut off the mountain resort's communications. The villains can do this themselves by cutting the telephone cables. If we're hosting the scenario in modern times, the players are likely to claim they have cell phones. This isn't really problem -- cell phone jammers are legal and easily available. A small one that would fit in a suitcase would be sufficient to blanket the entire resort hotel. Even better, anyone trying to phone into the hotel would simply think that his connection's phone was turned off, so there's no clue to the outside world at all. Of course, if the people at the hotel were held incommunicado for too long, presumably someone would get suspicious, but we only need to hold them hostage for a day or two for the scenario.

Step Three - The Wow Finish

Every scenario should have a great climax. The upcoming ritual gives us a terrific possibility. In addition, if the investigators have somehow managed to contact the authorities, the police could show up (in a helicopter) just as the ritual is performed and some kind of awful frost-breathing monster shows up to destroy said police helicopter and show the players that mere human techniques are of no avail against the forces of the Unknown. Or, perhaps the cops show up safely and there is a big gunbattle in which the investigators are trapped between the cops and the villains. Trying to get from the resort to the relative safety of the police without getting mistaken for a bad guy and shot might be interesting, especially given that there is likely to be tear gas and smoke blanketing the area at the time. (You can provide gas masks for the villains if you need them immune to the tear gas. Might be even scarier to have them NOT immune and firing off shots randomly around them as they choke and wheeze.) 


Step Four - Finalize the Plot

Okay, the situation is that an evil cultist, committed to an asylum for his activities, has recruited four lunatics and escaped. He has arrived at a "mountain resort" and taken the player-characters hostage, among others. Either tonight or tomorrow night (depending on how much time you want to give your players), the "planets will align properly" so he can perform an evil ritual, and he no doubt plans to sacrifice his hostages at that time. What will happen if the PCs don't interfere? The villain will try to keep his victims under control and terrorized. To keep his insane buddies happy, he'll let them kill a few people for fun. During the ritual, he'll sacrifice his hostages and achieve his results. It's probably best to let the results be unspecified, so that you can adjust them to the situation at hand. You may not know until the actual event whether you want the ritual to summon a monster, or turn the cultist into a monster, or whatever. If the ritual gets thwarted by the players, then you can have it be as fearsome as you want (after the fact). Example: Keeper - "As you throttle the cultist and stop his chanting, the huge black hole in the air starts shrinking. Just before it vanishes you see Cthulhu's dread visage peeping through." Players - "Wow we're glad we stopped THAT!" If the ritual is NOT thwarted by the players you can have it segue into your next adventure - now they have to figure out a way to close the gate / eliminate the monster / stop the plague of madness / whatever you wanted to have happen as a result of the ritual. Another possibility - if you want to get your players to the Dreamlands or somewhere else exotic, have the ritual transport them all there.

Step Five - Create the Characters

Work out personalities and "trademark" features for the main villains and good guys. In our case we have five villains, and we may as well as work out the basics for all five of them. Naming characters can be a pain. I have three techniques for getting character names for my adventures.

1) I use names of childhood friends that my players won't know.

2) I get them out of a phone book opened at random. (Only good for locals.)

3) I get them from a movie filmed in the character's nation of origin.

I used technique #3 here -- I simply looked up an early Peter Lorre movie on the internet and stole the names of the first five cast members. Hans Albers, Anna Sten, Heinz Ruhmann, Ida Wust, and Kurt Gerron. Two are female, but that's good. Now for the bad guys. Since the scenario probably will revolve around the players' interaction with them, we need more distinctive personalities than most cultists get to have. Here goes: