Intro to Basic Roleplaying, the system behind the BRP compatible horror game "Of Hearth & the Harrowing"

We talk a lot about how Of Hearth & the Harrowing is a Basic Roleplaying (BRP) compatible horror game. In the last blog post I talked about why we chose BRP for the game. In this post, I want to take a step back and talk to those people who have never played a BRP game before, I'll introduce you to the mechanics for BRP and get you up to speed on the basics.

Released under way back in 1980, the system has been around for a very long time. Later editions were released since, and I really learned about it after the release of the "Big Gold Book" in 2008. Then about 5 years ago, they announced it would be opened up under the Open Game License with an accompanying SRD 5. Then in 2023, an updated version of BRP was released as the Basic Roleplaying Universal Game Engine. This is the current version, and came out under the ORC License. To its fans it is still just BRP. All the people I talk to at Chaosium make no real distinction between the old 'gold book' and the new hardcover. Its all just BRP. And finally, this is the version that Of Hearth & the Harrowing uses. Well, mostly.

BRP is a very modular system. A lot of its core parts will feel very familiar to veteran gamers. Stats or attributes (called characteristics in BRP) measure your character's Strength, Charisma, Intelligence, and Dexterity. BRP adds in Education (an optional characteristic we don't use in Of Hearth & the Harrowing), Size, and Power. For those familiar with D&D Power is sort of the Wisdom stat of BRP. It represents not worldly wisdom though, but instead willpower and force of will. Size is how big you are. Characteristics generally range between 3-18, a familiar bell curve that veteran gamers are very familiar with.

The next important and familiar area on the character sheet is the skill section. Skills are the lifeblood of all actions in BRP. If you want to do something active, you are likely rolling against a skill. Characteristic rolls are much more rare, and they represent resistances or defenses, more than something active that you are trying to accomplish.

Skills in BRP are all a percentile value*. To attempt any action with that skill means trying to roll under the skill on a percentile die. Roll equal to or under means you succeed. Roll very low, and you might score a critical. Roll very high, and you suffer a fumble. BRP as written also has a Special Success which is lower than your skill target, but not as low as your critical target. The math to calculate this on the fly never seemed to really be worth it to me, so for Of Hearth & the Harrowing, we removed Special Successes, and widened the critical range.

* Quick side note: Dragonbane and Pendragon both use d20 instead of percentile dice. For the rest of the article, if I say percentile, assume I mean "or d20 if talking about Dragonbane and Pendragon". It would just be annoying to type or read that every time, so just assume that.

Any skill you use successfully, gets an XP check mark if it does not have one. Later, when you do advancement, that skill may grow. This is the core thing for me that sets BRP games apart from D&D and other games like it. You grow what you use, not based on going up a level in a class. Professions matter very little after character generation. In some BRP games they give you the chance to grow one of your profession skills in addition to things you used during adventuring, but that is a very small extra bonus, not your main advancement method.

Next in some BRP games there are powers, passions, and personalities.

Let's talk first about powers. The core rulebook presents five different kinds of powers that gamemasters can mix and match, pick from, or ignore altogether: Magic, Mutations, Psychic Abilities, Sorcery, and Superpowers. Each have different rules and systems. I won't go into all of them, but any that require success rolls to activate (many don't) use a percentile roll and consider the power as a separate skill. This is the core of the Magic system and became the core of the Powers system that we use in Of Hearth & the Harrowing. We use it for both maneuvers (non-magical powers) and spells (magical powers). Each power is its own skill, and the more you use it the better you will become at it over time, just like other skills.

Finally, one of the things that sets apart games like Runequest, Pendragon, and also Of Hearth & the Harrowing is the use of the passions and personalities systems. While many games have different versions of characteristics and skills, many games lack depth of characters that have any meaningful impact on the game. Not so with passions and personalities. The idea is to have a list of things that a character is passionate about and a set of scores that help define how a character acts or behaves.

Each BRP game that uses these has a bit of a different way they use them, but all of them have mechanical, not just roleplaying impact. Each is always still a percentile like skills. They could be used to augment a skill roll. For example, if your character is fighting for their honor, they can roll against their Honor passion to augment a fighting skill check. If they are successful in the honor roll, they get a bonus to the fighting skill check, but if they fail, then it makes the skill check harder. If they fumble they might lose some honor as they become despondent over their lack of honor in the current situation.

Personalities come in pairs. For example Courageous/Cautious or Outgoing/Reserved etc. Each pair add up to 100%. If you have a Courageous of 60% then your Cautious will be 40%. When one goes up, the other goes down, they are paired opposites that naturally resist in opposition to each other. Either can be used as an augment if the situation is appropriate.

The thing that is great about passions and personalities, is they really help you as a player define your character's nature. Then, when you are in a tough bind and trying to figure out how your character might react to a situation, you can use these as guides for roleplaying. They are not straight jackets, you can act against them, but if you have something particularly high and act against it, your gamemaster can have you make a roll to see if you can avoid adjusting the particular score towards the way your character is acting.

How do all of these rules come into play in a BRP compatible horror game? Well, percentile systems with a critical chance often mean that anything dangerous can be deadly, and that really helps add to the horror feeling of the game. The personalities and passions mean that what matters to the character is exposed into the system and that gives levers to really get at what drives the character, and can help to define not just the things they love, but the things they fear. Overall, BRP really helps us to drive home the fear and horror of the setting for Of Hearth & the Harrowing, and I can not think of a system I would rather use for the game.

As a 200+ page rulebook, this blogpost just starts to scratch the surface of the mechanics of BRP, but hopefully those of you who have not played a bunch of BRP now have some core concepts of the game system. All of the above systems are a core part of Of Hearth & the Harrowing. Future blog posts will go further into depth in specific mechanics of the game. Until then, may all your percentile rolls be criticals!