The Most Loved and Most Loathed Rules of Call of Cthulhu

Call of Cthulhu has always stood apart from other TTRPGs. This is not a game about heroes conquering evil. It’s a game where knowledge is dangerous, ignorance is bliss, and the best-case scenario often involves escaping with your life (and, if you’re lucky, your sanity). The system itself has remained remarkably consistent over the years, which speaks to its design strengths—but that doesn’t mean every rule is universally loved. Some mechanics are brilliant, reinforcing the cosmic horror tone perfectly, while others are infamous for frustrating even the most seasoned investigators.

The Most Loved Rules

1. The Sanity System

The sanity mechanic is the crown jewel of Call of Cthulhu. Unlike most RPGs where the only things you need to worry about are hit points and resources, this game forces you to confront the psychological toll of encountering the unknown. Seeing an eldritch abomination or reading a tome of forbidden knowledge doesn’t just put you in physical danger—it chips away at your mind. And that’s what makes the game so engaging. Every investigator is on a downward spiral, and the real challenge isn’t necessarily survival—it’s staying sane long enough to make a difference. The gradual (or sometimes instant) descent into madness is one of the most memorable aspects of the game, leading to incredible roleplaying moments where investigators develop phobias, manias, or just go completely off the deep end. It’s pure Lovecraftian horror in mechanical form, and it works beautifully.

2. The d100 Skill-Based System

One of Call of Cthulhu's greatest strengths is its simplicity. Rolling a d100 against a percentage-based skill is as intuitive as it gets. There’s no need to reference convoluted tables or apply excessive modifiers—you know your character’s capabilities at a glance. The elegance of this system allows for a lot of naturalistic roleplaying, where players can focus on the narrative instead of crunching numbers. Plus, the way skills improve—by actually using them in-game—adds a layer of realism and immersion that many other RPGs lack.

3. Pushing Rolls

One of the more recent additions to the system (introduced in 7th edition) is the ability to “push” a failed roll by trying again—but with consequences if you fail the second time. This is an elegant mechanic because it gives players a choice: do you accept failure and move on, or do you gamble on an even worse outcome? It aligns perfectly with the themes of Call of Cthulhu, where curiosity often leads to doom, and desperate investigators are willing to take reckless risks for answers.

The Most Loathed Rules

1. Combat is Brutal—Sometimes Too Brutal

Nobody comes to Call of Cthulhu expecting heroic battles, but even by horror RPG standards, combat can feel excessively punishing. Investigators are not meant to be warriors, but the combat system often leaves them feeling utterly helpless. Many players (especially those coming from D&D) are shocked when a single gunshot can take them out of commission or when a physical confrontation with a monster is essentially a death sentence. While this reinforces the game’s horror themes, it can sometimes feel unfair—especially if the Keeper throws combat encounters at the party without warning or escape routes.

2. The Luck Mechanic (7th Edition)

Luck is a divisive rule in Call of Cthulhu. In earlier editions, it was a static attribute primarily used for determining fortunate or unfortunate circumstances. In 7th edition, players can spend Luck points to modify rolls, allowing them to succeed when they otherwise wouldn’t. On one hand, this is a helpful tool that prevents frustrating failures in crucial moments. On the other hand, it can cheapen the tension of the game. If players hoard Luck and spend it at the right times, they can avoid many of the system’s built-in dangers, reducing the sense of helplessness that makes Call of Cthulhu so compelling. Some Keepers mitigate this by limiting Luck regeneration, but in its default state, it feels a little too forgiving.

3. Character Creation Can Be Unforgiving

Building a character in Call of Cthulhu is straightforward, but it’s also easy to make a completely ineffective investigator. Unlike D&D, where most characters can contribute in some way even if they’re poorly optimized, Call of Cthulhu punishes bad skill distribution harshly. If you don’t invest in essential skills like Spot Hidden, Library Use, or some kind of social ability, you may find yourself struggling to participate. This isn’t a huge issue for experienced players who understand what’s needed, but newcomers often end up with characters who are just… useless. And in a game where survival is already a challenge, that can be discouraging.

My Final Thoughts

Despite its few rough edges, Call of Cthulhu remains one of the best horror RPGs ever made. The sanity system, intuitive skill checks, and risk-reward mechanics create a uniquely immersive experience that’s hard to replicate. Sure, combat can feel merciless, and some mechanics may need tweaking depending on the group, but that’s what house rules are for. If you lean into the game’s themes—embracing mystery, paranoia, and the inevitable descent into madness—then Call of Cthulhu delivers an unforgettable roleplaying experience. Just don’t get too attached to your investigator… because chances are, they won’t be around for long.