Minærva McJanda talks about doubling up: running Heart: The City Beneath with custom advances to let you try combining two classes at once.

I’ve been running Heart for my home game recently, and after a lot of roleplaying all of our characters got to places where their starting class felt limiting. As it currently exists, Heart doesn’t have Extra Advances like Spire, so my group and I worked together to find a potential solution we would all enjoy. I’d also been playing a lot of Ball X Pit, which delights in taking two mechanics and shuffling them together, and so I tried to bring some of that energy into the game too. Here’s what we came up with!

The Basic Rules

If you wish to become something more down here in the Heart, you’ll have to let it make you strange. 

It starts with an initiation; maybe that’s just encountering an NPC who’s a member of the desired class, or maybe it’s being exposed to the same force that puts others on the same path. It’s different for every class.

Once you’re initiated, you gain that class’s Minor and Major catalyst beats in addition to your regular beats. Hit one catalyst beat, and some part of your core abilities shifts to accept it; see Incorporating Core Abilities, below, for more guidance on that. From that point on, beats of that type from your calling allow you to pick advances of that type from either class – for example, if you hit the Minor catalyst beat you’d then be able to take Minor advances from either class whenever you hit a Minor beat from your Calling. 

Hit the second catalyst beat, and the transformation is complete; your core abilities are now pervasively altered, and any Minor or Major beats you hit let you pick advances from either class. I’d encourage you to look at all the Major advances from both classes and see if there’s too much overlap between them; in that case, instead of letting the character take both Majors and double-dip in a way that might be unfun at the table, consider removing one of the Majors and appending its Minor sub-abilities to the other. 

Is it possible to unlock Zenith advances from your second class? That’s for your group to understand. The Heart holds its secrets close.

Catalyst Beats

Cleaver

• Initiation: Be served the flesh of a heartsblood creature and eat it.
• Minor: Eat the flesh of a Heartsblood Creature you killed.
• Major: Eat the flesh of a sentient person you killed, who was at least a Risky adversary.

Hitting the Minor incorporates The Red Feast into one a core ability. Hitting the Major incorporates Heartsblood into a core ability.

Deadwalker

• Initiation: Meet a ghost or encounter the Grey.
• Minor: Take Fallout from spending too long in the Grey.
• Major: Take Critical fallout and somehow survive it.

Hitting one lets you Enter the Grey with an hour-long ritual, and leave it easily; hitting both brings the time down to 10 minutes. Hitting the Major manifests your Death and gives it a drive to protect you, as per Death Follows Close.

Deep Apiarist

• Initiation: Get lulled into a daze by the buzzing of an apiarist hive.
• Minor: Consume the honey of glyph-marked bees.
• Major: Visit a place that is a crucial part of Apiarist infrastructure and take some of its bees for your own.

Hitting one incorporates Release the Swarm into a core ability. Hitting a second incorporates The Hive.

Heretic:

• Initiation: Visit a site holy to the Moon Beneath.
• Minor: Comprehensively forsake your previous faith.
• Major: Meet an emissary of the Moon Beneath and receive their blessing.

Hitting one lets you use Ministrations to lead a service in an established shrine to heal a minor Blood or Mind fallout. Hitting a second lets you lead a service anywhere (adding +1D4 to a delve’s resistance), and let celebrants instead downgrade a major blood or mind fallout to minor. 

Hound

• Initiation: Find a badge of the 33rd and take it with you.
• Minor: Hurt a civilian because your badge told you to.
• Major: Capture whatever killed the previous holder of your badge and bring them back to a haven to stand trial.

Hitting one lets you mark stress to Fortune once per situation. Hitting the second also gives you mastery from suffering Fortune fallout.

Incarnadine

• Initiation: Use force or manipulation to turn a deal in your favour.
• Minor: Go deep into debt.
• Major: Use your soul as collateral, and have it wired to explode.

Hitting the Minor incorporates The Cost of Doing Business into a core ability. Hitting the Major incorporates Mutually Assured Destruction into a core ability.

Junk Mage

• Initiation: Consume a psychoactive substance as part of a ritual.
• Minor: Take D8 or greater Mind stress after doing something you knew would hurt you.
• Major: Steal something from one of the old gods of the Heart

Hitting the Minor incorporates Sacrifice into a core ability. Hitting the Major incorporates Ravening Knowledge into a core ability.

Vermissian Knight

• Initiation: Protect others from a heartsblood creature, or get into a fight at a station of the vermissian.
• Minor: Find an established Knight to train you.
• Major: Hunt a train and gather spoils that can be fashioned into armor.

Hitting one lets you spend a Technology or Occult resource to supercharge a machine, dealing stress to a delve or healing stress from you equal to the amount rolled on the resources’ dice.

Hitting a second one gives you your own suit of Vermissian Knight armor, and the full Vermissian Plate ability. 

Witch

• Initiation: Be exposed to the Witch-blood disease, or take Echo fallout.
• Minor: Drink deeply from the blood of a Cursed landmark.
• Major: Earn (or take) the blood lineage of an established witch.

Hitting the Minor incorporates Crucible into a core ability. Hitting the Major incorporates True Form into a core ability.

Blightborn

• Initiation: Breathe deep in a Wild domain.
• Minor: Take a dose of hallucinogenic fungus, voluntarily taking the Weird fallout.
• Major: Get someone to voluntarily feed themselves to the fungal colony.

Hitting the Minor incorporates Colonise into a core ability. Hitting the Major incorporates Whisper Network into a core ability.

Crawler

• Initiation: Find a resource within a hidden passage or a dangerous trap.
• Minor: Hide a useful item within your body.
• Major: Wander alone into an unknown part of the Heart and trust it to deliver you back to safety.

Hitting the Minor incorporates Every Tool a Hammer into a core ability. Hitting the Major incorporates Inexplicable Loot into a core ability.

Snail Pilgrim

• Initiation: Have a vision of a place deep in the Heart, and commit to making a pilgrimage there.
• Minor: Become an important figure in the society of a haven.
• Major: Find the shell of a great beast and a means of transporting it.

Hitting one gives you the gelatinous flesh of a mollusk, giving you +1 Blood protection as per Pilgrim Shell. Hitting a second turns the haven you have chosen into ooze within the shell, letting you retreat into the shell as per Pilgrim Shell and letting you Remove Shell.

Witness

• Initiation: Encounter an artwork that fills you with passion or curiosity.
• Minor: Create a piece of art from scratch and perform it before strangers.
• Major: Decide on pseudonyms for every one of your companions, drawn from your favorite artwork. Only refer to them with those names from now on.

Hitting the Minor incorporates Inspirational into a core ability. Hitting the Major incorporates Observer into a core ability.

Incorporating Core Abilities

This is more an art than a science. Remember: you’re trying to tell a story with these mechanics, and make the character’s class something unique to that particular person and their context. It’s not really possible to give you step-by-step guidance for this because I don’t know your characters, but I can give some worked examples:

Deadly Heresy

A Deadwalker is finding religion, and seeks out the Temple of the Moon Beneath. The core abilities of the Deadwalker are:

• Death Follows Close, which causes the Deadwalker’s death to lash at enemies the first time each session the Deadwalker suffers Major Blood, Echo or Fortune fallout.
• Enter the Grey, which lets the Deadwalker travel to the Grey with a 10-minute ritual and leave it easily.

At the shrine to the Moon Beneath, the Deadwalker forsakes her previous faith in the Solar Pantheon, casting it aside. This hits the minor catalyst beat; now, when she Enters the Grey in a religious shrine, everyone present can heal a minor Blood or Mind fallout as per the Heretic’s Ministrations ability.

Later on, she travels to the Moon Garden to directly entreat her goddess. Somehow she makes it out of that encounter not only alive but blessed. Following that encounter, the transformation is complete, and Enter the Grey now becomes:

Moonsilver Flight

As the moon tracks across the skies, you spirit your surroundings from one realm to another. Roll Delve + Religion to enact this ritual. Over the course of a ten-minute prayer to the Moon Beneath (adding +D4 to the delve’s resistance) you blur the borders between realities. In the grey light of the Moon Beneath, all player characters who took part can remove one Minor Blood or Mind fallout, or downgrade one Major Blood or Mind fallout to Minor. At the end of the service, you can choose to guide the celebrants back to reality or into the Grey. Exiting the Grey is a simple enough task for you Deadwalker and those you ferry across; it’s a Delve+Religion roll for anyone else.

Blood Magic

A Junk Mage is tired of going to others for power, and has decided to seek out the Witch infection in order to have an internal battery to pull on. The core abilities of the Junk Mage are:

• Ravening Knowledge, which gives mastery on casting spells when Mind Stress is high enough.
• Sacrifice, which lets them destroy Occult resources to gain protection against the stress of casting magic.

After travelling to Last Orders and drinking deep of the predatory structure’s blood, they’ve hit their first catalyst beat, incorporating Crucible into a core ability. This is simple enough, replacing Ravening Knowledge:

Crucible of Knowledge

Your blood sings with arcane secrets. When your Echo stress is 4 or higher, roll with Mastery when attempting to cast a spell. At any time you may roll a D6; if it’s over your current Echo stress, add that much stress to Echo.

Later, this fledgling witch seeks out Magi-Mal’s Domain, and following gruelling trials are adopted as one of her blood-children. With this, the once-Junk Mage gains a True Form, replacing Sacrifice as follows:

Arcane Form

Magic boils in your blood, waiting to turn you into a flickering, hungry horror. Whenever you want to, or when you suffer Major Fallout, you enter your true form – describe it. When in your true form, you roll with mastery on Discern checks and gain +1 protection against any stress incurred while casting a spell, but all other checks become Risky. At the end of the current situation, you revert to your humanoid form.

Your turn!

So, that’s the core idea for this system. Take it away, and have a go! See what kind of weird creations you can come up with, and put their mechanics together in a way that compels you. If it appeals, share what you came up with on our discord!

– Minærva McJanda (@minahoneybat on bluesky)

With thanks to my co-designers and playtesters for these mechanics: beatrix McJanda, Hazel bug-jelly, and E. R. F. Jordan (@erfjordan on bluesky)