Elthos RPG Overview

Elthos RPG: Core System and Mythos Machine Briefing

This briefing document summarizes the core tenets and key mechanics of the Elthos Role Playing Game (RPG) and its supporting web application, the Mythos Machine, drawing primarily from the Elthos Core Rules Book, Elthos.com website, and related materials.

I. The Elthos RPG: A Flexible, Story-Oriented, "Old School" System

The Elthos RPG is presented as a highly distilled, light-weight, and flexible tabletop role-playing game designed to "minimize grunt-work and maximize creativity." Originating as a "homebrew" in 1978, it carries a distinct "Old School" flavor, aiming to simplify and address issues found in early D&D systems.

A. Core Philosophy:

• Simplicity and Fast-Action Play: The system prioritizes "simple-to-run, fast and exciting game play" by utilizing "tiny-numbers math." The default "One Die System" (ODS) uses a single 6-sided die for most actions, keeping "number-crunching required during play as minimal as possible."
• Creativity and GM Empowerment: Elthos is explicitly "designed for Gamemasters who want to create their own Worlds of any genre or setting you can imagine." The rules provide a framework and examples, but the "creative aspects of World Weaving [remain] safely in your own hands where it belongs."
• Flexibility and Customization: The system is "entirely customizable," allowing GMs to "configure your Worlds in an enormous number of ways" and define their own "Elements for your Worlds (Weapons, Armors, Skills, etc) with your own internal custom rules." It is explicitly "genre-neutral," capable of handling "From Troglodytes to Space Marines."
• Balance of Story and Wargaming: Elthos seeks to "balance the story aspect with wargaming style tactical challenges for those who want both in their game." While encouraging "Descriptive Narratives" to enhance immersion, it also offers "Optional Rules" for more tactical combat.
• GM Adjudication and "Do What's Fun": The system does not attempt to "create an individual Rule and/or Chart for every possible thing." Instead, it relies on the GM to make "appropriate judgment calls wisely" and "retro-fit the events and circumstances so that they make sense in the context of the World." The overarching principle is "do what's fun."
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B. Core Mechanics: The General Resolution Matrix (GRM) and One Die System (ODS):

• Single Resolution Mechanic: All questions of success and failure, including combat, non-combat skills, and mystic powers, are resolved using a "single General Resolution Matrix (GRM)."
• Difficulty vs. Skill Level: The GRM determines the "Chance To Succeed (CTS)" based on the relationship between a Character's "Skill Level" (or "Attack Level" in combat) and the "Difficulty Level" of the task (or "Armor Class" in combat).
• 1d6 Default ("One Die System"): By default, players roll a single 6-sided die. A roll equal to or higher than the CTS value indicates success. A "6 is always considered a success, while rolling a 1 is always considered a failure."
• Optional Dice Systems: For a "more nuanced gaming experience," the rules include "Optional Dice System for using two, three, or four 6-sided dice." These systems have different GRM Roots (e.g., 7 for 2d6, 11 for 3d6, 14 for 4d6).
• Tiny Numbers Math: Most numeric lists and modifiers range from 1 to 6 (for 1d6 system), making calculations quick. Even small differences in levels or requisites have a significant impact.
• "ODS Bound" (Optional): This optional rule limits key variables like Attack Levels and Armor Classes to a range of 1 to 6 to keep in-game math "ultra-light" and ensure "a good old lucky shot isn't always possible" for weak characters, and strong characters can still fail.
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C. Character Generation Highlights:

• Races: GMs can create their own races, each with typical levels, requisite ranges (Strength, Wisdom, Dexterity), and movement points. Player characters typically choose from "Human," "Dwarve," "Elve," and "Halfling."
• Requisites (ST, WS, DX): Characters have three core requisites (Strength, Wisdom, Dexterity) ranging from 1 to 6, each providing a bonus (-2 to +2) that affects damage, life/mystic points, or armor class. Requisites can be generated randomly, assigned from a point pool, or allocated.
• Adventure Classes: Characters select a class (Thief, Fighter, Spell Chanter, Cleric) or a "Freeman" class (no requisite requirements, but skills cost double). Multi-classing is possible.
• Character Level: Represents proficiency and confidence, increasing with "accumulated (successful) Experiences." New levels grant skill/mystic point improvements and additional Life/Mystic Points.
• Heritage & Starting Money: Determined by a 1d6 roll, influencing starting wealth and social status.
• Skills and Mystic Powers: Learned by spending "Skill Learning Points" (SLP) and "Mystic Learning Points" (MLP) gained at each level.
• Primary Skills: Class-specific, used at Character Level +1, and earn "Prime Experience."
• Elective Skills: Can be learned by the class, but earn "Elective Experience" (less than prime).
• Unlearned Skills: Used at 1st level (or 1/3 Character Level with optional rule).
• Mystical Skills (Heroic Feats & Kung Fu): Allow for the expenditure of Mystic Points to augment skill effects.
• Armor System: A detailed system where armor affects not only "Armor Class" (chance to avoid being hit) but also "Dexterity Modifier" (DXM), "Damage Absorption" (DAB), and "Movement Modifier" (MOV).
• Trade-offs: Wearing heavier armor increases damage absorption but typically reduces dexterity and movement, impacting attack level.
• Key Terms: ACM (Armor Class Modifier), DXM (Dexterity Modifier), DAB (Damage Absorption).
• Customization: GMs can configure armors, including their ACM, DXM, DAB, and MOV values, within the Mythos Machine. The tutorial highlights how selecting different armor types (leather, chain mail, plate mail) involves strategic choices for players balancing defense against mobility and attack efficiency.
• Weapons: Categorized by type (Light, Medium, Heavy, Mystic) with associated Damage, Damage Bonus, Attack Level Modifier, and cost. Ranged weapons have optimal indoor and outdoor ranges.
• Life Points & Mystic Points: Calculated based on Character Level multiplied by Strength or Wisdom requisites, respectively. These represent physical and mystical endurance. Negative points lead to detrimental effects, including unconsciousness and even death/brain death.
• Mystic Attack Level (MAL) & Mystic Armor Class (MAC): Determined by Character Level + Wisdom Bonus, used for resolving mystic combat.
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D. Combat & Skills Usage:

• Narrative vs. Tactical Combat: GMs can switch between descriptive "Narrative Combat" and more detailed "Tactical Combat" using maps and defined rules.
• Experience Gains: Awarded for successful skill and power use, and for defeating opponents. Calculations are provided for both combat and non-combat experience, with an "Experience Gain Multiplier" to moderate advancement speed. Combat experience is generally shared among the victorious party.
• Recuperation & Channeling: Life and Mystic Points recuperate over nights of sleep. Characters can "Channel" Mystic Points into Life Points (and vice versa) in emergencies, but with potential negative consequences for negative Mystic Points.
• Mystical Powers: Spells (for Spell Chanters) and Miracles (for Clerics), powered by Mystic Points. Mystic Powers have properties like Range, Duration, Effect, Geometry, and Cast-Time, all customizable by the GM.
• Flexibility in Casting: Mystics can "shape the casting" by adding "Bonus MP" to increase a power's MAL, Damage, Range, or Duration.
• GM Crafting: GMs are encouraged to create new mystic powers by defining their properties and assigning a "Power Level."
• Alignment System (Hidden): A "math-based Alignment System" is mentioned as secretly embedded in the core rules, influencing "Avatar Powers" granted for high alignment scores.
• Tactical Combat Rules (Optional): Detailed rules for movement, zones of control (ZOC), positional attack level modifiers (PALM), total defense, and shielding, designed for map-based combat. ZOC is particularly significant for controlling space and forming "Extended Battle Lines."
• Critical Hits & Fumbles: Resolved by rolling additional dice after an initial 6 (Critical Hit) or 1 (Fumble), leading to enhanced success or catastrophic failure. Optional rules can modify the likelihood of these events based on character level.
• Disengaging & Subduing: Rules for attempting to escape combat or subdue an opponent without killing them.

II. The Mythos Machine: The Digital GM Companion

The Mythos Machine is a "browser-based web application" that complements and supports the Elthos RPG, providing a "comprehensive and fully integrated Gamemastering Toolbox and World Weaver's Studio."

A. Key Features and Mission:

• Game Prep Services: Seamlessly integrated with the Elthos rules, it handles "number crunching," helps "structure your World's places, campaigns and adventures," and acts as a "record keeping butler."
• World Creation and Configuration: Allows GMs to "create, configure and maintain your Worlds Online" in any genre, populating them with custom "Weapons, Armors, Races, Classes, Items, Spells, Cultures, and other 'Things'."
• Character Generation and Management: Players can "easily generate their Characters" according to the GM's world configuration, "maintain the ongoing histories of their Adventures, and keep notes." The Mythos Machine "performs all of the Elthos RPG calculations required to do so."
• Time-Saving and Organization: Aims to "Save time. Focus on the creative aspects of your game. Keep a searchable record of all characters, places, campaigns and adventures in your worlds. Have fun!" It is described as a "great organizer and time saver."
• Sharing and Community: GMs can "share your creations with other GMs on the system if you so choose," fostering a "Mutual Collaboration Society."
• Evolutionary Service: The Mythos Machine is "intended to continuously improve over time, so what it does today is likely only a glimmer of what it may do tomorrow."
• Not Required for Play: While a valuable asset, the Mythos Machine is "not at all required for you to enjoy the Elthos RPG," as the Core Rules Book provides everything needed for "Pencil & Paper Tabletop RPGs."
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B. Two Core Aspects of the Mythos Machine:

The World Weaver's Studio:World Building: Enables creation, configuration, and population of worlds with custom "Things" (Races, Classes, Equipment, Cultures, Currencies, Skills, Mystic Powers, etc.).

Story Tracking: Allows creation of a "hierarchal tree of Places, Campaigns, Adventures, Events" to record game stories and determine experience gains.

The Gamemaster's Toolbox:Character Management: Supports online character generation, assembly into "Adventure Groups," and "Auto-Generate entire Adventure Groups by Race, Class and Level."

Print Reports: Provides "Print Reports" for adventures, characters, and combat trackers, usable for "local or virtual use."

III. Key Themes and Important Ideas:

• GM-Centric Design: Elthos strongly emphasizes the Gamemaster's role as creator, adjudicator, and storyteller. The system provides tools and a flexible framework, but the "World Weaving" is firmly in the GM's hands.
• Simplicity vs. Nuance: A recurring theme is the balancing act between simplified mechanics (e.g., ODS, tiny numbers) for fast play and optional rules (e.g., multi-dice GRM, tactical combat) for greater detail and nuance. GMs are encouraged to tailor the complexity to their group's preferences.
• Narrative Focus: Despite its "old school" wargaming roots, Elthos encourages "Descriptive Narratives" from the GM to enhance player immersion and bring the world to life, moving beyond mere statistical reporting. The concept of "Retrofitting Dice Rolls to the Story" reinforces this.
• Customization is King: The extensive customization options for races, classes, equipment, and especially mystic powers highlight the system's adaptability to any genre or setting the GM envisions.
• Digital Assistance for Traditional Play: The Mythos Machine serves as a modern digital companion designed to offload tedious calculations and record-keeping, making the GM's life easier without forcing a digital-only playstyle. It streamlines the "grunt-work" so GMs can focus on creativity.
• Strategic Player Choice: The design, particularly in combat and armor selection, aims to encourage "Smart Play" by making players consider trade-offs and seek tactical advantages. The armor system tutorial perfectly illustrates these strategic decisions.
• Community and Collaboration: The Mythos Machine's "Mutual Collaboration Society" and "World Things Trading Post" suggest a vision for a shared ecosystem of creative content among GMs.

In conclusion, Elthos RPG offers a streamlined, customizable, and GM-friendly system for tabletop role-playing, heavily supported by the Mythos Machine to facilitate world-building and game preparation, all while promoting a balance between flexible rules and immersive storytelling.