Designing a New OSR Game

October 31, 2018

So lately I've been delving back into the world of OSR role-playing games. In my past several years of playing only modern games, I'd forgotten what it felt like to play an OSR game. I miss the simplicity and the speed of combat. I especially miss the very real sense of danger that my character would die, and I'd have to start over from scratch.

I decided to look at the original source material, a few recent entries into the genre, and some other inspirational material and come up with my own OSR rules.

This blog post represents the first part of that journey.


One of the core themes of OSR games is simplicity. Character classes have very few details to them, and certainly not a deep progression arc. The game is less about characters becoming more mechanically powerful and more about putting these characters into new situations and seeing what they do. In that sense, at least, it's a role-play heavy style.

Another expression of the theme of simplicity is in the resolution mechanic. If you take into account the optional rules from the original game (and here I'm referring specifically to Moldvay Basic), there were attribute tests, but they were simple d20 roll-under-ability-score affairs. There were no bonuses to such rolls. Combat was a little weird with the AC to-hit scheme. I don't miss that part, at least.

A New Game Begins

So for this post, let's say that this game of mine will begin with the basics and riff on that. The original game included only a handful of classes, and three races were classes in themselves. In my game, let's make this a little more complex.

There are classes, and there are races. Classes remain very simple, with only a couple special abilities to give them a bit of flavor. Races are added to the mix, so that each character has both a race and a class, but they also are very simple. This gives any given character less than half a dozen special abilities from both choices, and this doesn't change beyond first level.

"What about spells?" I hear you say. Well, in this system, spells are going to be treated much like equipment. Each spell is a limited-use magic item, probably in the form of a spell-gem or something similar. Magic-using classes will be able to collect and use these in different ways. Non-magic-users won't even be able to hold the things.

"Does that go for divine magic too?" No, divine magic - called miracles in this game - uses something much more freeform. A user of divine magic prays to a deity to enact a miracle through them. This will be a unique roll - I'm toying with a few ideas here.

Most tests not covered by special abilities or other game rules will be roll-under ability score tests. I'll use the original game's 3d6 ability score generation, and d20 roll-under test. That seems just fine.

Saving throws are reduced to a single type. It's basically a hail-Mary play that can save your character from something awful by making it less awful, but still bad. It's also a roll-under target, but it's set, not random. You also only get one per game session.

I like weapons all doing the same damage, so we're going back to that. We'll make things more interesting, though, by making all weapons have a special feature. That will keep them from feeling same-y.

More on these topics is coming in further blog posts.