Mythras

Mythras is a d100 fantasy TTRPG from The Design Mechanism for groups who want detailed, dangerous combat and characters rooted in a culture, a career and the cults or orders they belong to. It is the rules engine formerly sold as RuneQuest 6, and it works as a toolkit: the core book gives you rules, five kinds of magic and advice for building your own world rather than a finished setting.

It is a weaker fit if your group wants a light game or a GM who can open a book and run tonight. Combat has a real learning curve, and the GM is expected to decide which weapons each combat style covers, which cults exist and how magic works in the world.

What the game is

Mythras is a percentile game written by Pete Nash and Lawrence Whitaker and published by The Design Mechanism. Characters roll under a skill on d100, combat uses hit locations and wounds, and advancement comes from improving skills. There are no levels. The default assumption is fantasy of a fairly grounded, Bronze Age to medieval kind, but the same rules support historical, urban fantasy, science-fiction and superhero settings through supplements.

The core book covers character creation, skills, equipment and economics, combat, five magic systems, cults and brotherhoods, more than 50 creatures (including some non-human player species) and a long Games Master chapter. A running example, Anathaym's Saga, follows one group of characters through the rules.

Publication history and editions

Nash and Whitaker wrote the second Mongoose edition of RuneQuest before founding The Design Mechanism. In 2012 they published RuneQuest 6 under licence, a single 446-page softcover with everything needed to play. In 2016 Chaosium did not renew the licence for the RuneQuest name and later used it for its own RuneQuest: Roleplaying in Glorantha, so The Design Mechanism re-released its game as Mythras.

The Design Mechanism describes Mythras as the same system in an updated format: new layout and art, a few rules tweaks, and some new material such as extra combat special effects and spirit combat effects. The book got shorter (about 300 pages) because the layout is tighter.

What you need to play

You need the Mythras core rules, percentile dice and a d20 for hit locations. The PDF is on DriveThruRPG and from the publisher, and print copies are made to order: a hardcover through DriveThruRPG and a paperback from The Design Mechanism's store.

To try the system first, download Mythras Imperative, a free cut-down version of the rules. It covers character creation, skills, combat and creatures in a form meant for several genres, and is released under the ORC licence so other designers can build games on it. It does not include the full magic systems or the cults chapter.

Supplements, settings and modules

The Design Mechanism publishes a lot of support. Rules add-ons include Mythras Companion (vehicles, chases and expanded social conflict), Mythras Firearms (guns from muskets to blasters), Mythras Factions, a GM screen and combat cards.

Settings cover a wide range. Monster Island is a sandbox fantasy island, and Shores of Korantia is a full fantasy setting. Mythic Britain, Mythic Rome, Mythic Constantinople and Mythic Babylon are historical settings with some magic. Classic Fantasy adapts the rules for old-school dungeon crawling, After the Vampire Wars is modern urban fantasy, Destined covers superheroes, and Luther Arkwright is parallel-world science fiction. There is also a steady run of short adventures, some of them free.

Third-party ecosystem

Because Mythras Imperative is open, other publishers have built on it. Frostbyte Books' M-Space is the best-known example, a science-fiction toolkit, and smaller publishers sell adventures and settings. Mythras shares its roots with other d100 games, so adventures written for RuneQuest or Basic Roleplaying can be adapted.

Digital tools and VTT support

A community-built Mythras system for Foundry VTT is linked to the official Mythras Discord, and Roll20 has a Mythras character sheet. Neither is sold by the publisher as an official VTT product.

Core rules and play structure

To succeed, roll equal to or under your skill on d100. A roll of one-tenth of your skill or less is a critical, and very high rolls are fumbles. Skills often go past 100 for veteran characters. Many contests are opposed rolls, where the better level of success wins: a Deceive roll against an Insight roll, for example. Difficulty grades raise or lower the skill before you roll.

Characters have seven characteristics (Strength, Constitution, Size, Dexterity, Intelligence, Power and Charisma) and derived values such as hit points for each body location, action points and Luck Points. Luck Points can be spent on rerolls or to survive a blow that would kill you. Between adventures the GM gives out experience rolls, which players spend to try to improve skills or to learn new ones.

Characters and advancement

Character creation starts with culture (primitive, nomadic, barbarian or civilized), then career, which together decide the standard and professional skills a character starts with. Players then spend free points, and fill in community and family, contacts, background events and social class. Combat skills are combat styles, which cover a group of weapons that make sense for that culture, such as a hoplite style with spear and shield.

Passions are one of the game's best ideas. They are percentage scores for loyalties, loves, hatreds and beliefs, such as Loyalty to the Duke or Hate the Raiders. A Passion can boost a roll when it applies, and the GM can test it when two loyalties pull in different directions. There are no classes and no levels; characters improve skill by skill.

Signature mechanics

Special effects. When you attack or parry and get a better level of success than your opponent, you choose a special effect on top of normal damage: trip them, disarm them, hit a chosen location, cause bleeding, bypass armor or force a surrender. This is what makes Mythras combat feel different from older d100 games. Fights often end within a few rounds, once someone is knocked down, disarmed or badly wounded.

Action points. Each character has a small number of action points per round to spend on attacks, parries, evasion and other actions, so deciding when to parry and when to attack matters. Weapon reach, hit locations, armor by location and serious and major wounds all add detail.

Five magic systems. Folk magic is small, common magic almost anyone can learn. Animism deals with spirits, theism with miracles granted by gods to their worshippers, sorcery with studied spells you can shape, and mysticism with trained inner powers. Each of the four advanced kinds needs two skills, and each ties into the cults and brotherhoods that teach it.

Cults and brotherhoods. Temples, shamanic traditions, sorcery schools, mystic orders and secular organizations all use the same rank structure. Joining one gives a character training, magic, allies and obligations, so advancement ties into the setting.

What play feels like

A Mythras session tends to be slower and more deliberate than many fantasy games. Players think about which combat style to use, whether to fight at all, and what their cult expects of them. Fights are tense and short. A good special effect can end a fight in one exchange, and a major wound can cost a character a limb. Outside combat, Passions and opposed rolls do a lot of the work in social scenes.

Running the game

Expect more prep than in most fantasy games, at least at the start of a campaign. The GM decides which cultures, careers, combat styles, cults and magic exist in the setting, or picks a published setting that has done that work. The Games Master chapter is long and useful, and it encourages GMs to treat optional rules as dials. Many groups start with the basic combat rules and add reach and other details later, and cheat sheets or the combat cards for special effects help.

Campaign fit

Mythras is built for campaigns. Skill growth, Passions, cult ranks and community ties all pay off over months, and the many settings support long play in very different worlds. One-shots are possible with pregenerated characters, but character creation and the combat learning curve make it a poor first pick for a single evening.

Reception

On DriveThruRPG the Mythras core PDF averages 4.8 from 119 ratings, 99 of them five stars, and Mythras Imperative averages 4.5 from 100. We found no major award win for Mythras or RuneQuest 6.

A long Runeblog review praises the special effects, the magic systems, Passions and the GM chapter. Its main criticisms: movement in combat is awkward, the combat detail is a lot to learn, skills well past 100% strain the rules, and having one more action point than an opponent is a big edge.

Where it is strongest

• Combat special effects give every exchange a real choice and keep fights short.
• Five distinct magic systems that a GM can match to any setting.
• Passions, cults and cultures that tie characters to the world.
• No classes or levels, so characters grow in the direction the player chooses.
• A free, open version of the rules and a large catalog of settings.

Where it can frustrate groups

• Combat has a steep learning curve, and the first sessions can be slow.
• The GM has to build combat styles, cults and magic for a homebrew world.
• Movement and positioning rules are loose next to the detail of the rest of combat.
• Very high skills and action point gaps can unbalance fights in long campaigns.
• If you want Glorantha specifically, Chaosium's RuneQuest is the game for it.

Content notes

Combat injuries are described concretely, including lost limbs and bleeding wounds. Historical settings may involve slavery, religious conflict and war, depending on the supplement. Content depends mostly on the setting the GM chooses.

Best starting path

Read the free Mythras Imperative and run one fight with its combat rules to see whether special effects suit your table. If they do, buy the Mythras core rules and either build a small setting with a few cultures and cults, or pick up Monster Island for a ready sandbox. Add rules like weapon reach once everyone is comfortable.

Research notes

Last checked November 13, 2026.

• DriveThruRPG: Mythras (formats, page count, ratings, AI disclosure) and DriveThruRPG: Mythras Imperative (ORC licence, contents, ratings)
• The Design Mechanism: Mythras core rules (contents, creatures, Anathaym's Saga, changes from RuneQuest 6, print-to-order paperback) and the publisher's catalog
• Wikipedia: RuneQuest (edition history)
• Runeblog review of Mythras (April 2019) (RuneQuest 6 page count, licence history, rules detail, criticisms)
• Foundry VTT: Mythras system