On the background and basics (Them Deeper Bones, design diary 1)

Petri Leinonen
5 min readApr 20, 2021

Them Deeper Bones is a retro adventure game I’ve been working on since December (2020, if you stumble here sometime in the far future). I am a bit hesitant to call it OSR since I don’t really identify with that particular scene all that much, but let’s just say it shares a lot of the DNA and borrows from those games. The current full text can be found at https://themdeeperbones.com/, available in freely comment-able mode. With these diaries (if I ever write more than one), I’ll first start by talking about what I’ve got in so-far and what my line of thinking has been with each subject, and hopefully at some point turn them to actual diaries of what I’ve been working on lately.

Hex Map with two structures and an X to mark the spot
A Hex Map of Apple Vale and surrounding areas, the setting of TDB playtests


The main influence for the game comes from what made “those old games” feel so much fun for me. Two biggest games I spent my childhood playing were Frank Mentzer’s BECMI D&D and the Advanced Dungeons & Dragons 2nd Edition. Those two had a great way of focusing on both the role-playing but also the system aspects. To do something, you had to do it and explain how you did it. But as there were things that couldn’t be properly or easily role-played, you still had good, solid mechanical systems to play them through the use of dice and creative ideas.

I’ve recently had the wonderful opportunity to play Dungeon Crawl Classics, a game that aims to capture the raw feeling of everything being new and exciting just like those old games did. And I love playing the game very much, even if it sometimes goes for the eccentric just for the sake of it. But the one thing that really stood out to me in that was how differently magic was dealt with from the standard Vancian form, so I’m not hiding my source of inspiration to how magic is dealt with in TDB. (As well as other, smaller bits here and there). I should also give a shout-out to some other ones, like Sharp Swords and Sinister Spells, and Blades in the Dark. And pretty much every game I’ve played over the years. The influence-list keeps on growing daily.

But most of all, this project comes from a place of rekindling of the love to those old games. Before D&D 3e came out, I was a truly passionate fantasy gamer, but the emphasis that particular game put on system mastery and number crunching instead of role-playing put me off the whole genre for years. I realised I wanted to have a system I could play with that felt like I wanted these games to feel. So I began building one.

The Basics

Them Deeper Bones, at its core, is a simple system. As I put it to someone who asked to explain it:

d20, roll high. Get bonus dice to rolls instead of static bonuses. Dice are there to save your butt when you’ve as a player role-played yourself into a pickle. Magic is not full-on reliable Vancian resource, but more random and unique. There are only 3 classes. Base stats are more in line of “player skill” approach than those in D&D. And there is a kick-ass combat system that is mostly compatible with red box monster stats.

To drill down further on each part:

  • The mechanical bits of the system are designed in a way they always can be simplified towards a single rule, and for Them Deeper Bones that is to roll the dice to try get high. The typical die to roll is the iconic d20.
  • One thing that came up during the playtesting was how much fun it was for the players to add another dice result to the d20 roll instead of adding a static number to it. So, all bonuses that are added to a roll are in form of extra dice.
  • Although I’ve spoken about the dice now, the big idea for actual gameplay is that most of the game is the players tackling most of the challenges presented through role-play, while the central mechanic is the Saving Throw, that is more of a second chance for when the player has caused some danger to fall on their character than a “skill check” to solve problems.
  • Magic in D&D doesn’t feel magical to me. It is extremely controlled and more like a set of one-use tools that allow for clear effects meant to bypass certain challenges reliably. The magic system in Them Deeper Bones retains the tool-like approach to spells being specific effects, but adds a randomisation system, so that unless they have ample time, a spell result will be unpredictable.
  • There is no cleric class — the three main classes are expert, fighter and magic-user. The religious vampire-hunter/healer that the cleric archetype is built upon can be easily rolled from the other classes, and as hit points are not a resource that needs to be managed the same way it does in D&D, the need for a straight up HP manager role / healer is not relevant.
  • The base stats in the game are Physique, Reflexes, Stamina, Knowledge, Insight and Power. While you can map the regular six-set to these, there are some clear differences in how they work. Biggest being the Knowledge / Insight / Power trio versus the classic Intelligence / Wisdom / Charisma one and how the latter are extremely hard to match sometimes with a game that pits player ingenuity against the challenges in the game. “My character would be intelligent enough to solve this!” or “My character is so charismatic that I shouldn’t have to role-play this scene, but instead roll the dice.” Renaming and redefining the stats eases this part a lot.
  • And then there’s the combat system. This whole thing originally started as a damage hack for the red box after someone made the comment “If you abstract things enough, a single successful attack should reduce your hit dice by one.” And I started wondering how that could be made interesting. The combat system will be the focus of one of these design diaries, but at this point it probably suffices to say that any attack can be instantly lethal but there is a chance to survive pretty much any attack, while the combat keeps getting more dangerous the longer it takes.

So that’s the gist of it. It’s now April, and the working version of the manuscript is 95 pages long (published version is something like 92). I’ve run several playtests and improved the system according to them, but the point of these design diaries is to get other people than those in my immediate circle to read and comment on what I’m doing with it. I’m extremely grateful to have you along for the journey.