Hello and Welcome to Part 2 of my look at the Harmony Drive SRD by Cat McDonald. If you didn’t read part 1, I really recommend it. If you don’t have time though, one or two bits of review. First, Harmony Drive as three main design pillars it has been built on:

  • Self-Expression – Players are encouraged to “engage with problems in their own style“ without worrying about holding the rest of the group back.
  • Teamwork – Success and failure is largely build around team achievement by encouraging ensemble work in their use of skills or combos of skills and spells.
  • Difficult Choices – Sometimes to achieve success, you have to pay the cost. In Encounters, the players can choose to take hits in hopes of greater gains in the future

In the last part I talked about game mechanics that reflected these parts individually. Today though, the Encounter and Magic systems that I will talk about here embody all three of the design pillar and I would point to them as the defining mechanics for this SRD.

The Encounter System in Harmony Drive

The encounter system is the primary means the game simulates extended periods of conflict or trials of the characters. But how does it tie into the pillars?


Self-Expression is demonstrated in the encounter system as it can easily mechanically simulate engaging a wide verity of trials. This could be resolving a crisis situation like a natural disaster, a combat situation, negotiations, a bank heist, and so on. This provides extreme flexibility for the Encounter since the challenge or challengers can literally be anything or anyone opposed the goals of the players from a vice-principal on hallway patrol to a hurricane to a mob of henchmen to a virus.

Self-Expression is also demonstrated in that there are multiple ways to potentially overcome an Encounter. Normally these are expressed in Destroying (or Defeating) the opposition, Redirecting the opposition, or Outlasting (or Escaping) the opposition. Each of these have different narrative outcomes and are likely to have varying difficulties. For example, let’s look at the stereotypical D&D undefeatable enemy, the Tarrasque. Destroying the Tarrasque is going to be incredibly difficult and Redirecting it to attack somewhere else somewhat less so, but Outlasting it in a target-rich environment like a city like might not be all that hard. Well, at least as long as you don’t mind leaving the monster to run rampage over everyone else you just left behind.


Teamwork is demonstrated by how the characters approach the situation. All the players act first before the Challenge in the Encounter does. The various and diverse actions and spells the players could commit to combat the Challenge narratively do not directly impact the Challenge mechanically, but instead contribute to the Party’s Advantage Pool. This Pool can be used to Advance one of three potential Goals until the party has managed to achieve it.

Difficult Decisions

Difficult Decisions come into the Encounter system because the Advantage Pool is also the only potential way to thwart the Challenge’s actions on the GM’s turn. If the Advantage Pool does not have enough successes to defend the party or if the party chooses to not defend for some reason, then the action is automatically successful. The Challenge is able to limit their options for the next turn or harm the party in a mechanical or narrative way.

By combining all of these elements together, the Encounter tool could simulate a whole host of situations that the players are acting against to best fit the setting of the game. In a Medical Serial drama could be a crisis in an ER surgical hall. In a Stardew Valley-like estate or farming sim, a blight killing the crops could be an Encounter. In a game like the recently released Chinese restaurant TTRPG, Jiangshi: Blood in the Banquet Hall, Harmony Drive’s encounter system could simulate a stressful night in the kitchen, dealing with vampires, or dealing with a racist health inspectors all with the same tool.

You players want to make Rocket Surfing the hot new thing? Encounter! You Challengers are force, gravity, and bow shock heating. Your Goals are “Cutting an Awesome Line” [defeat], “Hanging on for Dear Life” [outlast], or “Bailing (Without Burning)!” [redirect]

Harmony Drive and Magic

The Magic System in Harmony Drive is simultaneously fluid and costly. 

The fluidity is demonstrated in the way spells are created. Each player starts with ~6 Personal Spell Pieces. These pieces are single words, normally ones that have a thematic connection to your game setting or have a descriptive application. For example, you might have “Flaming,” “Fang,” “Ice,” “Haunting,” “Tending,” or “Passage.” The scene that the characters are in will also have a set of Spell Pieces to go along with it. These may be attached to things in the scene or some sort of other outside influence

The spell is created by combining one of the character’s spell pieces with a scene spell piece to create a two-word spell. The player then describes how the spell will work and what they want the spell to do. The player and GM work together to decide if this fits the narrative and how much the spell is going to cost.

Now, Costs are just as important as the spell’s effect because each character has a limited amount of magic to draw from. In some settings there may be consequences by pulling from it too much. For example, in Cat’s Heroic Chord using more and more magic causes a dissociative state in the character. Other systems may not have a progressive consequence, but all of them should have a hard cap that limit how much power a character can channel without resting. This cost makes the use of magic strategic despite the flexibility of not needing to deal with leveled spell slots or memorizing spells like in some of the larger TTRPG systems.

As you can see, a game built around the Harmony Drive system is going to have flexibility, creativity and teamwork at its heart, something that I hope to carry through in my own creations very soon. If you would also like to participate in the Harmony Jam, feel free to join the community at Cat’s Heroic Discord server!

One Reply to “Harmony Drive #2 – Exploring RPG Engines”

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.