Mythras Imperative is an Open, ORC Licensed, version of the Mythras ruleset. This document offers a comprehensive, but not exhaustive, set of rules, including character creation, skills, rules for certain typical situations, combat, and magic – more than enough to get both players and Games Masters started, and form a solid basis for further development. Mythras Imperative is compatible with the Mythras core rules, and other ORC licensed percentile gaming systems. Its companion volume, Classic Fantasy Imperative, is also completely compatible and released under ORC, meaning that the two Imperatives can be easily combined.
Mythras Imperative is published using the ORC License. The ORC License provides a way for game creators to openly share the mechanics of their game and allows for downstream users to freely use, modify, and re-share adaptations of these game mechanics.
What is openly shared under the ORC is known as Licensed Material, and includes the broad functional elements of the game, such as stat blocks, game rules, character attributes, and the methods and systems inherent in playing the game, as well as anything else the licensor explicitly wants to share. The license is broad and lets you use the Licensed Materials globally in connection with printed books, video games, podcasts, AI, or any other technology that may exist or be created in the future. The vast bulk of the content found in Mythras Imperative constitutes Licensed Material.
What is not shared under the ORC is known as Reserved Material and includes trademarks, world lore, story arcs, distinctive characters, and visual art. We have listed Reserved Material in the ORC Notice, below.
Under the ORC License you can use, share, adapt, and build on the Licensed Material however you see fit, so long as you give proper attribution in the form of a notice in your published work. This notice both credits the upstream licensors and their contribution to the work, as well as providing an easy way for downstream users to credit the author of the work in which the notice appears. By using material licensed under the ORC, you automatically agree to license out your game mechanics in your published work under the same terms. If you develop your own Reserved Material, that is your exclusive property.
Mythras Imperative is licensed under the ORC License located at the Library of Congress and available online at various locations including Paizo.com and others.
All warranties are disclaimed as set forth therein.
This product is based on the following Reserved Material:
Mythras, The Design Mechanism Copyright 2016, Written by Pete Nash, and Lawrence Whitaker
If you use our Licensed Material in your own published works, please credit us as follows:
Based on Mythras Imperative, Written by Pete Nash and Lawrence Whitaker, and published by The Design Mechanism, Copyright 2023
Note that Mythras Imperative's parent games, Classic Fantasy and Mythras, published by The Design Mechanism, are designated as Reserved Material under the ORC license.
If you wish to draw upon content found in either Classic Fantasy or Mythras, please contact The Design Mechanism about the separate Mythras Gateway License, which allows for Reserved Material to be accessed, free of royalties, but with some conditions regarding approvals and attribution.
The following are also considered Reserved Material:
Mythras Imperative – as a name, save for when used in attribution, including its logo.
Mythras – as a name, save for when used in attribution, including its logo.
All artwork, graphics and trade dress found in Mythras Imperative
Mythras Imperative is a d100 or percentile system. Percentile dice, or 1d100, are used to resolve key actions – skill use, combat, magic casting, and so on. It is a roll-under system, meaning that the target number is expressed as a percentage (Athletics 65%, for instance), and both the Games Master and player are looking to roll equal to or less than this target number, using 1d100, to achieve a Success. It is quite easy to replace the 1d100 with a d20 if preferred, and all percentages can be divided by 5 (round up) to gain the target number for a d20 roll. Athletics 65% would become Athletics 13, in our example.
However, 1d100 offers a great deal of flexibility and nuance that underpins the whole game, so our recommendation is to try the 1d100 approach first. While it may seem counterintuitive to have to roll less than something (in many games, higher is usually better!), having a target number expressed as a percentage range that one needs to roll within makes it easy and simple to see your chances of success, and allows for quite a few 'dice tricks,' such as Opposed Rolls, Criticals and Fumbles, and a few other things explored later in these rules. Percentile roleplaying has been around since the earliest days of roleplaying and is a firmly established game system with a tried and tested core mechanic that is flexible, intuitive, and tends to fade into the background during play.
Long time owners of Mythras will note that in some places the Mythras Imperative rules have been simplified. This has been done so that a Games Master may more quickly introduce the game to new players with a minimum of fuss.
On some occasions you will be required to divide numbers – typically the rating in a skill (such as for determining a Critical Success, which is 1/10th of the skill's value). Whenever a division result creates a fraction, always round up to the whole number. So, for instance, 1/10th of 63% is 6.3; this is rounded up to 7.
Mythras Imperative uses the standard polyhedral dice set: d4, d6, d8, d10 d12, d20 and d100. Additionally, the following dice are called for:
d2: Roll any die. An odds number equals 1 and evens equals 2. Or flip a coin.
d3: Roll a six-sided die; 1-2 = 1, 3-4 = 2, 5-6 = 3