Potentials and Resistance
You have much potential, Adventurer
Potential Scores
Each creature is made up of a set of 8 scores called Potentials. Each of these Potentials represent a character's capacity to success relating to a given category. Potentials are split between Physical and Mental: Physical Potentials relate to a creature's bodily and physical capabilities, whereas Mental Potentials relate to a creature's intellectual and mental capabilities. The 8 different Potentials are as follows:
Physical Potentials
Might: A creature's strength and athleticism is represented by its Might score. This score may determine a player's ability to move large objects, scale a wall, or grab ahold of a ledge while falling.
Finesse: A creature's quickness and flexibility is represented by its Finesse score. This score may determine a player's ability to navigate quickly through a market chase, tie a knot, or evade someone's grasp.
Nerve: A creature's heartiness and stamina is represented by its Nerve score. This score may determine a player's ability to ride a horse nonstop, recover from illness, or remain clear-headed while partaking in substances.
Seep: A creature's ability to manifest and maintain their physical form is represented by its Seep score. This score determines a player's ability to physically incorporate the arcane without harm, call upon form-altering magic, or resist physical arcane effects.
Mental Potentials
Instinct: A creature's ability to be aware of their surroundings and others' emotions is represented by its Instinct score. This score determines a player's ability to spot a target from far away, determine if someone is lying, or dodge a sudden incoming attack.
Wit: A creature's ability to quickly discern patterns and remember information is represented by its Wit score. This score determines a player's ability to recall details about history, glean an understanding of a mechanism, or understand the workings of synthetic arcane enchantments.
Heart: A creature's ability to maintain spirit in the face of dread and navigating social exchanges is represented by its Heart score. This score determines a player's ability to convey messages nonverbally, haggle for a better price at the bazaar, or remain unfazed in the presence of horrific otherworldly entities.
Tether: A creature's ability to keep ahold of their sanity and manipulate dark powers is represented by its Tether score. This score determines a player's ability to resist mental arcane assaults, grasp the nature of ancient dwoemers, and wield the energies of the universe.
Resistance Points
Some abilities or perks may call for expending a Resistance point. Each Potential is considered to be a pool of Resistance Points equal to the Potential Score. Expending Resistance Points causes the Mixed success level threshold to increase during tests1. However, the Resistance pool shares the same threshold of strain on a character as a Potential's Stress track. Given a certain Potential, a Potential track can only hold a total number of Stress and Resistance points equal to the Potential Score.
In the example below, a player has 5 Stress points in an example Potential, and has expended 3 Resistance points. This makes a total of 8, which is equal to their Potential Score. This means a player cannot expend any more Resistance points (they are taken over by Stress), and if they take any additional Stress, it will trigger Fallout since the player cannot hold any more Stress (the slots are taken by Resistance Drain).

The meat and potatoes of gameplay
Skills
When a player takes an action that requires a certain amount of skill or luck, it often requires a Skill Test. A Skill Test is a Test associated with a particular Skill. Each Potential Score has three subcategories called Skills. Skill Tests are unique due to their potential for a creature to be proficient in the roll.
Here is the list of Skills organized by their parent Potential:
Might
Force - Contested strength, striking against an enemy, taking athletic action
Brace - Preparing against force, standing one's ground
Feat - Pushing past natural capability, breaking limitation, taking heroic tests of strength
Finesse
Sleight - Moving stealthily, ranged accuracy, manual deftness
Grace - Steadiness and balance, moving quickly
Squirm - Escaping restraint, avoiding anticipated threats
Nerve
Bear - Resisting physical effects of damage, continuing unfettered
Steel - Enduring strenuous wear unphased, resisting natural bodily response
Grit - Mind over body, maintaining clarity in moments of pain
Seep
Frame - Resisting arcane alteration, maintaining appearance
Draw - Adapting to surroundings, letting in warp
Form - Actuating physical change, becoming something new
Instinct
Reflex - Making quick decisions, avoiding unexpected hazards
Read - Honing in on a creature's behaviors, gleaning intent
Sense - Using the five senses, tapping into a sixth sense
Wit
Reason - Understanding patterns, puzzling and calculating
Recall - Remembering information, memorizing mundane facts
Esoterica - Intuiting the abstract, creating structure in the unknown
Heart
Aura - Expressing body language, signaling subtly, acting
Sway - Influencing others, deceiving, appealing
Hope - Inspiring others, resisting fear
Tether
Anchor - Resisting the effects of insanity, staying spiritually grounded
Grasp - Understanding the indecipherable, drawing from the powers that be
Weave - Conducting rituals, channeling raw warp
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See Sunder's Resolution System ↩