24 Hour RPG: Core Mechanics

I’ve nominally decided to call this 24 Hour RPG, Legends of the West. In this post I’ve cooked up a core mechanic that seeds normal distribution (bell curve of success) with the ability for any action to succeed, albeit with slim probability. Later, I’ll add ways to improve chances with additional mechanics.


This section explains the principal mechanics that power Legends of the West. Understanding how things operate should help players build characters that can effectively fill the concepts they want to explore. Optional rules are presented in sidebars, but just because this manual doesn’t consider a core rule optional doesn’t mean the players cannot change or ignore something that does not meet their needs. With that in mind, consider all the rules optional.


Legends of the West requires at least one player to be the Judge. The Judge’s role is to provide seeds of adventure for players’ characters to act upon and then facilitate conflict resolution once those character end up in hot water. It is a mighty responsibility to become the Judge, but it is the most important role at the table. Just remember, a Hanging Judge is just as likely to find himself swinging from the end of a noose as is her victims.


Most daring-do that a Legends of the West character attempts is determined by an Action Roll. Choose the Ability that governs the action that is being attempted and note any modifiers. The Judge may also impose additional circumstantial modifiers. Now, roll three six-sided dice (3d6), add any modifiers, and then compare the result to the Difficulty Rating (DR). If the total result meets or exceeds the DR, the action is a success. Other rolls, such as Effect Rolls or Damage Rolls may be required upon success as determined by the Ability’s description.

Not every little nuance a character does needs to be resolved with an Action Roll. Unless the action is critical to the telling of the tale, the Judge should just let it happen. So there’s no need to roll to see if a character can put her boots on or make a fire to cook a meal, unless failure would add to the drama. Like if lighting the fire means surviving a cold winter’s night in the mountains.

Legend Dice

Legend Dice provide a twist on the conventional Action Roll. A Legend Dice has the ability to explode. This means that whenever a Legend Die resolves at that its highest possible value (i.e. a 6 on a d6), then that die is rolled again and the results are added to the total. Legend Dice continue to explode until a result other than the highest value is rolled.

Legend Dice replace normal dice in the Action Roll, so a player never rolls more than three dice. Legend Dice can be used under three different circumstances:

  • Specialization: The character is specialized in the action
  • Grit: A character spends one Grit
  • Quality: The scene relates to a character’s Quality

No more than one Legend Die may be used in an Action Roll for each circumstance. For example, if more than one Specialization applies to an action, the character still only receives a single Legend Die. However, it is possible to have every die be Legend Dice in an Action Roll if all three circumstances apply.

Difficulty Rating

DR is either determined by the Judge, from an Opposed Roll, or  by the Ability being used, in which case the Difficulty Rating will be found in its description. For Action Rolls without a defined DR, consult the table below to determine how hard an action is to accomplish.

Difficulty Rating Table:

Difficulty Rating
Very Easy 5
Easy 10
Moderate 15
Difficult 20
Very Difficult 25
Insanely Difficult 30
Legendary 40

Ones & Sixes

Automatic success and failure is not present in Legends of the West by default. This means that there are some tasks that some character cannot ever achieve from a vanilla Action Roll. Spending Grit for a Legend Die might give a character a snowball’s chance in hell, but it’s very slim. The West ain’t for the faint of heart, kiddos.

Even so, interesting things do happen when a player rolls the maximum or minimum values of the dice on an Action Roll. When a trinity of sixes appear when all three dice are rolled ( not on individual Legend Die rolls), it’s called the Devil’s Mark and the character gains one point of Grit. When a trio of ones are rolled, that called a Weird, and the character gains three Grit. Achieving rock bottom failure has a way of hardening a man. These results may also have other consequences dependent on the scene.

Variance of Success & Failure

The potential effectiveness, or impotence, of an action is determined by the Variance of an Action Roll. Variance is calculated by finding the difference between the Action Roll and the Difficulty Rating. Every increment of five the Action Roll exceeds or falls short of the DR counts as a Variance of Success or Failure, respectively.

For example, if the total result of an Action Roll is twenty-four and the DR was fifteen, that action would have a Success Variance of one. Variance can mathematically be calculated by subtracting the DR from the Action Roll total and then dividing the difference by five, always rounding down.

The mechanical effects Variance is detailed in the description of an Ability. However, not every action or Ability will take Variance into consideration, but the Judge and players should feel free to improvise for effect when as the situation dictates.

Optional Rule: Critical Success & Failure

Whenever a Devil’s Mark is rolled, that action automatically succeeds even if the result does not meet or exceed the DR. If the result does meet or exceed the DR, the Devil’s Mark counts as an additional Variance of Success.

Whenever a Weird is rolled, that action automatically fails even if the result meets or exceeds the DR. If the result would already be considered a failure, the Weird counts as an additional Variance of Failure.

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