Hacking Call of Cthulhu

Our Acts of Evil campaign was on shore leave this week, as one of the players couldn’t come and play. (Yeah, I realized only belatedly that AoE doesn’t actually require group cohesion from session to session. I should have thought about that before.) Anyway, this being the case, we played a nostalgic one-shot of Call of Cthulhu. The prescription came along thus: I wanted to play something horrorful, for I have been studying the Call of Cthulhu adventures of fourth and sixth editions of the game for an article I’ve been trying to write. So it was to be CoC, except for one problem: that game never had a fully functional rules system.

Horror roleplaying has never been a particular thing for me; when I play something like My Life with Master, I’m not playing a horror game first. It’s just a drama roleplaying game with gothic props, and if the results are gut-wrenching and horrifying, it’s because that’s how the issues dealt with in the game are, not because I’m purposefully telling horror stories as the GM.

The only proper horror roleplaying game where you’re supposed to scare the players I ever played was Call of Cthulhu, which we played quite a bit during the ’90s alongside all those other games that got translated into Finnish around then. CoC was always a problem-child for me, rarely working to bring out real horror. The lurid macabreness was entertaining as well, though, and when CoC worked, it could be quite enjoyable. In hindsight CoC, Paranoia and Cyberpunk 2020 all worked in fundamentally the same way: there was a strong setting under the GM’s thumb, and his job was to bring that setting into play in concrete ways. I seem to remember that I did a pretty good job of that in Cyberpunk (although my Cyberpunk had more to do with hard scifi than cyberpunk at times), a passable job in Paranoia and a rather mediocre one in CoC.

(An aside: what the fuck is this? I go and google “Call of Cthulhu”, and I get some weird video game or something. Meanwhile, Chaosium’s page is somewhere off in la-la land. Good grief.)

Going back to all that, I don’t think I can run a one-shot of CoC using the BRP system CoC utilizes. Having to fill up that skill matrix, figure out equipment and all that is rather prone to take away from the focus of the game in some many ways. So instead, what I did was that I hacked up a bunch of simplified rules for the purpose:

Eero’s Cthulhu hack

All characters have three common attributes, which are Body, Education and Will. Furthermore, each character might have background attributes, which are used to determine skills. The player chooses the age of the character, and he’ll get one background attribute for each beginning decade of age after the first two. So a character on his third decade gets one background, while an old-timer on his seventh decade gets five. So far, so good.

Each attribute is expressed as a percentage, because that’s pretty, and the original CoC abilities would be percentified for ability checks anyway. The player rolls his abilities with an appropriate bell curve – in the actual session we used “roll three ten-sided dice for the tens, pick the middle one, and roll a ten-sided die for the ones, too”. This is so that the extremes of attributes don’t steal the spotlight. It is also rather appropriate to give the players a bit of control over the kind of character they want, so we allow the player to emphasize and de-emphasize attributes, both in equal number: the emphasized attribute gets the high die for tens, the de-emphasized one the low die.

The background attributes are player-defined and they depict typical skill-sets in the setting. An older character has several because he’s had more time to develop different careers. Appropriate examples are Policeman, Showgirl, Professor, the usual stuff. The actual character skills are derived from the background attributes as needed during play – check the attribute to see if the character has a notion of the skill in question, that kind of thing. If a character has several applicable backgrounds, he gets to check each and take the highest result for his skill.

So far, so good. The older characters are a bit at an advantage with their multiple backgrounds, though. That is fixed by determining that all characters have a bunch of Energy tokens, which are used for rerolls and whatever. Give each character 10, but deduct their age in decades. That way the younger characters get more energy and less skills, which makes everything right in the world.

Also, an important rule to nail the entirety down: whenever a character makes a skill check (skills derived from the background attributes, as we remember) , the check result is compared with the skill percentage as well as an appropriate primary attribute (one of Body, Education and Will). The skill comparison determines whether the character succeeds in whatever he’s doing, while the ability comparison determines whether the character loses a point of Energy. In other words, characters with skills much higher than the appropriate attribute can’t use the skill as much as they’d perhaps like. On the other hand, a character with a higher attribute than skill can fail securely, without fearing an energy loss. So the attributes are not used so much for independent attribute checks, like in CoC, but for determining the resource consequences of skill checks.

So that’s the basic structure. What happens to characters who lose all their Energy, and what Energy is exactly used for, is still not that clear. Likewise the important parts, like scene framing and adventure structure, are still vague – I’m using the CoC GMing instructions for those. The actual session of play was god-awful, but I’m not sure if it was my rules or the CoC play technique; I’ll need to experiment more to find it out. For those interested, here’s an actual play report with some detail of the session itself.


2 Responses to “Hacking Call of Cthulhu”

  1. What say you, Cthulhu? « Game Design is about Structure Says:

    […] say you, Cthulhu? 18.11.2007 — Eero Tuovinen Continuing on my last post, I’ll outline a theory of what investigative play in Call of Cthulhu is really about. […]

  2. Olorin Says:

    Itse asiassa tuo Dark Corners of the Earth on paikoitellen yksi tunnelmallisimpia tietokonepelejä mitä olen pelannut. Muutamaan otteeseen siinä vaaditaan ärsyttävää pikkutarkkuutta ja yleisesti ottaen pelintekijät eivät ole osanneet valita tekevätkö ammuskelu- vai hiiviskelypelin, mutta näistäkin huolimatta kokeilemisen arvoinen, ainakin niille jotka yleensä pyrkivät pelien parissa immersioon.

    En ole varma sainko pelistä suuremmin ideoita tai apuja CoC-pelinjohtamiseen, mutta jos pääsen jossain välissä pelaamaan ko. peliä, on minulla nyt ainakin jonkinlaisia apuvälineitä eläytymiseen, kiitos pelin antamien kokemusten.

    p.s. Varsin kiinnostavan oloinen systeemi. Josko tuota vaikka saisi joskus kokeiltua.

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