Exclusive sneak peek at Onyx Shards, fantasy RPG

In the spirit of showing my work, I’m sharing the latest draft of Onyx Shards, the fantasy RPG I’m close to finishing.

Apologies in advance for the long post!

Those of you who’ve been here a while might remember Onyx Sky, my post-apocalyptic attributes + skills step-die game:

Since August 2022, I’ve been adapting the Onyx system to the fantasy genre in Onyx Shards. As usual, I thought this would be a simple job, but it became a ‘Gilligan’s Island’-style task.

The key challenges have been re-thinking the martial skillset in Onyx Sky to support magic in Onyx Shards; my assumptions about how things work in a martial-only game needed to be reworked to incorporate magic.

Game Overview

  • Characters have six attributes: Strength, Agility, Stamina, Intelligence, Acuity, and Influence
  • Attributes have die steps; d6, d8, d10, d12, d16, d20
  • An attribute at d8 is average for a human, while d20 is elite capability
  • Characters can learn general, martial, and magic skills
  • Skills have specializations that reflect mastery, versatility, and focus
  • Action pools are used for attribute tests and attacks
  • In attribute tests, the action pool rolls against a fixed difficulty or opposed to another character’s action pool
  • Attribute test action pools include the character’s attribute die, a matching die for the relevant skill, and a matching die for a skill specialization
  • Attribute tests can achieve up to 3 successes
  • Action pools ‘upstep’ and ‘downstep’ with advantages and disadvantages
  • For attacks, the attacker’s action pool rolls against the target’s defense pool
  • Attack action pools include the character’s attribute die, a matching die for their skill (such as a weapon or magic training skill), plus any further matching dice for martial or magic techniques
  • Defense pools against physical attacks include the character’s Body die, an Armor die for worn armor, and additional dice for skills and specialized situational techniques
  • Defense pools against mental attacks use the character’s mental defense die and any further dice from mental defense specializations
  • Attacks can achieve up to 3 successes, and when an attack hits, the attack’s damage is dealt for each success
  • In combat, characters can take multiple actions by downstepping their dice

Design Goals

Onyx Shards is the second iteration of the Onyx engine, first used in Onyx Sky. Elements of the Onyx engine build on design concepts from pervious Hero Forge Games titles, including Forge Engine and Hero Kids.

Elements of the Onyx games – mostly the step die implementation – iterate and expand on ideas from earlier games, including Savage Worlds and Ironclaw.

As a product, the goals for Onyx Shards are:

  • Approximately 180 pages for PDF and 360 pages in print (less if possible)
  • Complete game in a single book: Characters, Game Rules, Game Mastering, Campaign Guide, and Adversaries
  • Full color artwork
  • Free version including Characters and Game Rules sections
  • Form fillable character sheet
  • Dice rolling marcos for Roll20

Genre and Setting:

  • While Onyx Sky is post-apocalyptic, Onyx Shards is:
  • Grounded heroic medieval fantasy
  • A world with magic and monsters
  • Implied setting (but not as strong as Onyx Sky)

The key mechanics of the Onyx engine are:

  • Attributes+Skills system
  • Attributes represented by dice, scaling from d6 to d20 (including d16)
  • Opposed rolls for attacks vs defenses
  • Core mechanic allows degrees of success
  • Energy for extraordinary physical, mental, and magic actions
  • Multiple actions allowed by downstepping dice

Beyond the basics of the Onyx engine, it also features:

  • Minimal default action set to streamline actions resolution
  • Single transaction attribute test resolution (in general play and in combat)
  • Skills work independently, no pre-requisites, no skill trees
  • Simplicity with depth: All skills cost the same
  • Minimal math; no addition, subtraction, or modifiers, only comparisons
  • Minimal derived attributes (Health and Energy)
  • Actions that introduce complexity are skills that players choose to learn, placing responsibility on the player to manage their character’s abilities (i.e. Dodge is a skill, which removes this transaction from the default attack resolution flow and makes the player responsible for enacting the action)
  • Associated mechanics; energy pool reflects extraordinary effort, all character abilities are grounded in in-world narrative
  • Progression system that allows limited vertical progression, then switches to horizontal development
  • No look-up or reference tables of abilities, effects, or options
  • System accommodates disparate character power through opposed rolls

The Onyx engine delivers the following gameplay experience:

  • Traditional gameplay style (associated mechanics, players control characters, GM controls the ‘world’, etc)
  • Tactical combat, with meaningful round-to-round choices
  • Consistent skill presentation between magic and martial skills
  • Balance between martial and magic, neither overshadows or replaces the other, and combat effectiveness is comparable
  • Characters can impose control on the battlefield and devise party-level coordinated actions to increase overall tactical effectiveness.
  • Magic spells can enhance or augment other character abilities, but cannot overshadow or obviate those abilities
  • Magic system encourages characters to focus on one or two magic schools

Onyx Shards paves the way for the future release of a universal version of the system, Onyx Shift.

Changes from Onyx Sky

Onyx Shards builds on Onyx Sky, the first release of the Onyx system. While the core system is identical between Onyx Sky and Onyx Shards, this iteration includes a variety of updates, the most important of which are detailed here.

Along with the major revisions, the text of the system is revised and updated, and all game examples throughout are updated for clarity and to reflect the shift to the fantasy genre.

Character Creation

Character creation is updated to incorporate magic skills, and the CP budget for attributes and traits in the default character build has increased by 4 to 54.


The major update to the Onyx engine is the inclusion of magic. Magic affects several parts of the game, notably the addition of the Magic Adept Trait and the Magic Grimoire, which chronicles the spell skills for each school of magic.

General Skills

The General Skills section is updated to reflect the fantasy focus of Onyx Shards and to streamline the number of Specializations for each skill.

Martial Skills

The martial skills from Onyx Sky have been reworked for Onyx Shards, splitting these into Basic Martial Skills, Specialized Martial Skills, and the Martial Tome of Battle. Furthermore, all of the skills in the Martial Tome of Battle are updated to align their design, usage, and costs with those of the new magic skills.


The equipment section has been entirely revised to reflect the medieval fantasy focus of Onyx Shards and to better clarify the requirements and characteristics of the different weapons.

Movement Distances

Onyx Shards updates the movement, attack, and perception distances to use paces instead of feet. A pace is 2 steps, approximately 5’, an easier unit of movement for VTT play and making conversion to metric trivial.

Energized Actions

A small but significant change from Onyx Sky to Onyx Shards is the expansion of energized attribute tests to include attack actions, not just non-combat tests. This gives characters a further use for their Energy in combat.

Actions and Reactions

The repertoire of actions and reactions available to characters is streamlined with the removal of the Block reaction from the default action set. The Block reaction was previously reserved for using shields. Shields now automatically apply their effect to the character’s Armor die, making the Block reaction redundant.

Death and Dying

The death and dying procedure in Onyx Shards is updated to use the new Unconscious and Dying conditions (see below), and incorporates a new Stamina test to determine whether a character ultimately lives or dies.


The original condition library has been updated with conditions for the various death and dying conditions, including Conscious, Asleep, Unconscious, and Dying.

Preview of Onyx Shards

If you’ve gotten this far, here’s the latest draft of Onyx Shards.

I’d love feedback on whether I’ve achieved my design goals, where I’ve not, and any inconsistencies, ambiguities, errors, issues, gaps, and gripes.


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