Call of Cthulhu is one of the oldest and most respected names in the world of horror RPGs, and for good reason. Its unique Jazz-age setting and flavorful mechanics helped it stand out from the pack early on, and it’s seen new players and content for nearly forty years since!
I Screamed Aloud That I Was Not Afraid… And the Others Screamed With Me
Call of Cthulhu takes place in our world’s Jazz Age — the decade of decadence and prosperity that occurred between the First World War and the Great Depression — with one major change: humanity is VERY definitely not alone in the universe. Just outside the bounds of CoC‘s world lurk a pantheon of horrifying, sanity-shattering god-things that view us with the same amount of empathy that we view bacteria. They sleep under the seas and in the dark places of the world, and they WILL awake one day soon.
Players take on the role of normal people who come into contact with these horrible truths. Maybe they refused to remain a victim in the face of such terror, or maybe they were just in the wrong place at the right time — either way, these Investigators delve into the mysteries that lurk in the shadows, and if they’re really lucky, they’ll escape from these adventures with just their minds shattered.
They Had Shape… But That Shape Was Not Made of Matter
Call of Cthulhu uses a variant of Chaosium’s Basic Roleplaying system, which uses d100s as its primary roll mechanic. Skills are represented as percentages — simply roll below a skill’s current percentage to succeed at a task. Given the relative mundanity of many of Lovecraft’s protagonists, there are MANY different skills for all sorts of different tasks, from Astronomy to Pharmacy to Mechanical Repair.
There’s no XP in the world of Call of Cthulhu, but that’s not to say that characters never improve. Every time that a player successfully uses a skill, the GM may tell them to put a check by that skill. At the end of each session, players may roll a d100 for any checked skill and see if the roll is over the skill’s current %. If they succeed, they get an additional d10 permanent points for that particular skill.
Of course, there are always exceptions, and in Call of Cthulhu, there is one skill that can never increase through usage: Cthulhu Mythos, a representation of the accumulated forbidden knowledge that a character has accrued. This skill only increases when one reads certain ancient tomes, encounters horrors firsthand… or more likely, starts to lose their mind as they are exposed to the nightmarish truth of their world.
Such Terrfying Vistas of Reality
One of the most noteworthy elements of Call of Cthulhu, and one of the elements other horror systems have attempted to emulate (to varying degrees of success), is its Sanity system.
At character creation, every character has a number of Sanity points equal to their Power statistic x 5 — on average, about 45-50 points. Every time that a character sees something particularly traumatic, they attempt to roll under their current total Sanity, and then subtract an appropriate amount of points. A door suddenly slamming shut for no apparent reason might only cause a single point of Sanity loss, and only then on a failure, whereas bearing witness to a character’s grisly murder might cause a loss of 1d6 points, even if one succeeds at keeping their composure. The way that this system is set up makes holding onto one’s mind a considerable challenge, as the madder you are, the harder it is to avoid sliding further into madness.
This struggle to deal with characters who are slowly becoming more and more damaged by their encounters with the supernatural is, I find, one of the most compelling elements of Call of Cthulhu. You always have to ask yourself, how much longer can I keep doing this?
The answer may often be “a woefully short time,” but that’s one of the draws of the system — the constant tension between up-front horror and creeping dread makes for an excellent system for tales of terror!