Osteomancy for D&D

Part of the Magical Practices Project

Part of the Osteomancy series

Last week, I walked you through my step-by-step thought process as I designed a homebrew thing (a class? A trait? A third title for a system that has not yet been fully laid out?) for a work-in-progress, still secret as of yet homebrew system. This week, I'll be adapting that creation into something useable for D&D 5e.

This post will be fairly short; all the thought process about the design went into last week's post, so I encourage you to check it out if you have not read it yet. This week, I'm going to focus on what needs to change for it to be usable in D&D.

That said, the osteomancy spells for D&D will not be available on DMsGuild any time soon. I'm working on a larger D&D-compatible project that is related to osteomancy, though it is still a pretty long distance away from being ready, and these spells will be included in that larger project. However, the project needs a lot more playtesting and revisions before it is ready to be public. I'm hoping for it to be ready sometime in 2024, but don't expect it soon.

What to Make the Osteomancer

The main decision in converting the osteomancy abilities that I developed last week into something usable for D&D was how to fit them into D&D's existing power framework. My first instinct was to make it a subclass, possibly of wizard or bard. After all, one of the abilities--foresight--is essentially modeled after the divination wizard subclass's Portents ability, and it is inspired more directly by someone else's homebrew Oracle class.

Certainly, from a lore perspective, this makes sense. In the world of my home game, it is essentially a particular type of wizard, unique to goblin culture, that practices this type of magic.

However, I also did not think that the three abilities that I have fit a full subclass. It certainly does not fit the core D&D rulebook options as a wizard subclass. I'd also need to pick spells that would complement the new abilities, but picking additional spells that did not tie back to the idea of throwing bones felt like it violated the premise of the homebrew. Especially as my second feature acts as a sort of modification to the spell augury, making this a feature and then giving access to augury as well just did not sit right with me.

Hence, new spells! In hindsight, this is a natural way to fit these abilities into D&D. Yes, it weakens the sense of cohesion: one character might not have all three of these spells. Yes, it still means that a character would have some spells about throwing bones and others that do not involve throwing bones. It's not perfect in adaptation, but I think it works better than it would as a subclass or a whole class. Plus, it creates new divination spells, an area that is much lacking in the published D&D spell lists.

Adapting Spells

In adapting the abilities we generated last week into D&D-style spells, there are only a few questions to answer.

The main one is about power level – what level should our new spells be classified as?

Our Tier 2 ability is the easiest starting point. It's essentially D&D 5e's Augury spell, with fairly minimal tweaks. So, keeping it essentially like Augury, we'll keep it in the same category as the base spell: a second-level spell that can be ritual cast and which has a casting time that prevents it from being useful in combat.

Our Tier 1 ability should naturally be weaker than the Tier 2 ability, but it does not have a direct spell parallel to take our numbers from because it is drawing from a class feature. I don't want to entirely scoop the divination wizard, however, and they gain portents at level 2, so our ability should be one that they cannot access until after level 2. This requires that our tier 1 omen needs to be a level 2 spell. I think it makes sense if it is also a ritual.

We also need to turn it back into something that fits D&D math, rather than the dice pool system of the homebrew project. For that, we can turn back to the homebrew Oracle class from Apothecary Press, and use their table as guidance for the power level of each roll.

Lastly, the tier 3 omen about prophecy should be considerably more powerful and late-game. I think it fits as a level 5 spell; that is when other major game-altering spells, like Modify Memory, start appearing, so I think it is fitting. I think this spell is not a ritual, because I don't want players to be able to spam prophecies.

That's it! Pretty much all that was left at this point was formatting the spells & tightening up some of the rules language for brevity.

Wrapping Up

Editing the three abilities from last week's post into spells was pretty simple. I strongly encourage you to check out last week's post if you did not read it. Today's probably made no sense if you didn't check out last week's.

Thank you as always for reading and supporting Veritas Tabletop! This marks the (temporary) end of the Osteomancy series. I'll pick it up again once I'm ready to start talking more about the larger project that I'm working on, but for now, the series is over. Stay tuned for our return to the regularly scheduled smattering of homebrew, history, and reviews.