Whisperspace

Rules Reference

Core Mechanics

D12 System

Simply put, the core mechanic is: roll 1d12 and add a modifier to it. This d12 is called the base die.

If you think of player action as a desire and a question (‘I want to climb the wall. Do I succeed?’), then you can think of this core mechanic as the GM’s way of answering that question (‘Roll 1d12 and add your athletics skill to it. If you get at least 8, you succeed climbing the wall’).

Want to fly a spaceship? Negotiate with terrorists? Shoot someone with a photon rifle? You’ll be rolling D12s and adding your skill modifiers for each one.

Difficulty Class

Difficulty Class (usually referred to as DC) is a target number a roll must meet or exceed in order to succeed. In the example above, the GM decided that a DC of 8 was required to successfully climb a wall.

DC can be mechanically decided in some contexts (such as combat; an attack roll must meet or exceed a DC determined by the weapon used, whether the target is behind cover, etc), while at other times the GM may be responsible for determining DCs ‘on the fly’.

Here’s a quick reference table to see some common DCs and what they might represent.

Task Difficulty

Difficulty Class (DC)

Description

Trivial

4

Finding milk in a fridge

Easy

6

Pouring milk into a glass

Standard

9

Hitting a dartboard with a glass of milk

Challenging

12

Flying a spaceship while drinking a glass of milk

Extreme

15

Climbing a slippery wall while drinking a glass of milk

Improbable

18

Throwing a glass of milk and getting all the milk back into its carton without spilling any

Degrees of Success and Failure

Not all successes (or failures) are created equal. In cases where the skill check rolled is significantly higher or lower than the DC, additional consequences may occur. Extreme successes may be rewarded narratively (at the GM’s discretion) or mechanically in systems such as combat. Conversely, extreme failures may bring about negative consequences in addition to the action’s failure.

In the wall-climbing example given above, the DC was 8. If a character rolls a 14 (6 over) they’re in extreme success territory; maybe they climb the wall in half the time, or maybe they move soundlessly while they do it. If the roll is a 4, however, they’re in extreme failure territory - maybe they climb partway, then fall and take damage, or an enemy is alerted to their presence.

Result vs DC

Outcome

Success by 0-3

Success

Success by 4+

Extreme Success

Fail by 0-3

Failure

Fail by 4+

Extreme Failure

Bonus Dice and Penalty Dice

Often, situations or tactical choices in Whisperspace will grant bonus dice or impose penalty dice to your character on a roll. Bonus and penalty may be thought of as two sides of the same coin; they perform the same but opposite function. Bonus and Penalty dice work alongside the core mechanic discussed above:

Bonus die: roll your skill check plus another d12. Choose the highest die rolled, then add your skill modifier to it.

Penalty die: roll your skill check plus another d12. Choose the lowest die rolled, then add your modifier to it.

Stacking Bonuses and Penalties

You may certainly come across situations in which you will receive a bonus die from more than one source. These are used together (they ‘stack’) up to a maximum of 2 bonus dice. The same is true of penalty dice. If you were to roll an attack with 2 penalty dice, for example, you would roll 3d12 (one from the attack action, 2 as penalty dice), choose the lowest number on any of those dice, then add your modifier to that number.

Bonus dice and penalty dice cancel each other out. Let’s say you receive 2 Bonus dice and 1 Penalty die on a roll. 1 Penalty die would cancel out 1 Bonus die, leaving you to make your roll with 1 Bonus die. 2 Bonus dice and 2 Penalty dice would equate to no Bonus or Penalty dice; you’d simply make the normal roll. 4 Bonus dice and 2 Penalty dice would leave you with 2 Bonus dice to roll.