Under the Hood

ShadowRealms’s core mechanics are based on what is referred to as the Realms Engine. The Realms Engine itself is built on a few key concepts.

The Core Test

The first foundation is the concept of the Test.

• Dice Pools: Tests are made by taking a variable number of dice—determined either by an Attribute rating or a variable factor such as Mana or Faith.
• Target Numbers: These dice are rolled to beat a target number, which is determined by the difficulty of the task being attempted.
• Modifiers: That difficulty can be modified (usually by a Skill or similar influence) to represent the condition of the test or the character’s specific ability to perform it.

Realm Points (RP) and Probability

Another foundation of the Realms Engine is the Realm Point (RP). An RP represents the ability to modify the probability of beating a test by exactly 1 point.

• Every time a target number decreases by 1 point (making the action easier to perform), that represents the value of 1 Realm Point.
• Other mechanical elements in the game are assigned RP values:
  • Dice: The dice rolled are worth 3 RPs each.
  • Advantage & Disadvantage: Because they represent a chance to reroll a success or failure, they are worth an additional 3 RPs for each level.
  • Adjustment Dice: When used, these are worth an additional 2 RPs for each step they are implemented or increased.

While this difference might sound negligible, it dictates how characters are defined. Everything is balanced by how a character is constructed and how that construction impacts probability.

• Aspects & Traits: These break down to represent the actual dice rolled to complete an action. Therefore, they cost 3 RPs per point.
• Skills: Because Skills directly modify the target number, their value is equated on a 1-to-1 basis with RPs.

Balancing Damage

Damage-dealing abilities are balanced in much the same way, as every attack consists of two components:

• The Dice Pool: The part of the attack that adds dice for rolling damage costs 3 RPs per additional die.
• The Modifier: The part of the attack that modifies actual toughness or attack strength costs 1 RP per point.
• Multipliers: The difference when calculating an attack’s value is that you multiply these numbers together. After figuring out that base number, the total can be further multiplied by being a multi-pronged attack (such as an Area of Effect) and by the specific Damage Type.

Balancing Narrative Traits

Traits function on a narrative level, which is much harder to balance on a raw probability basis.

• These are gauged within the logic of where abilities of similar levels sit compared to more straightforward, mathematical abilities.
• Finding a strict mathematical rationale for abilities like Flight or Night Vision is difficult; instead, each ability is evaluated by how it benefits the character, and its effects are placed accordingly.

Power Scaling

Powers scale based on their rating, with each power having a rating between 1 and 12.

• Each power costs 3 RPs per level, plus 1 base RP.
• A Level 0 power is worth 3 Realm Points.
• A Level 12 power hits the apex cost of 39 Realm Points.

Build Points vs. Realm Points

In actual character creation, a separate currency is used: Build Points. While this could initially seem confusing, Build Points and Realm Points serve different functions.

• Build Points: A tool used to construct a balanced, well-rounded character at a specific power level, fleshed out and ready for a specific setting. Abilities are often purchased on a geometric basis to maintain this power level.
• Realm Points (RPs): The raw mechanical weight under the hood. If characters were constructed out of pure RPs, you could end up with a well-balanced character or a completely exploited monstrosity inappropriate for the setting.

The important takeaway is that, at the end of the creation process, characters built with Build Points end up having roughly the same total Realm Point value.