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One engine. Any world.

Roll dice, build characters and run games without learning a new system every time.

Genre-Ready From Day One

The Core Rules are the rules. Catalogs are the settings.

Every AxiomRPG Catalog is built on this foundation without modification. The dice mechanics, Talent list, combat system, and advancement costs are the same in every catalog.

What changes: the world fiction, the lineages, the power traditions, the equipment, the factions and the threats specific to that setting.

Switching from a Modern urban horror campaign to a high fantasy campaign means picking up a new catalog, not re-learning mechanics.

  • A "Brisk" Investigator works in Hidden World and on Astraeus Terminal.
  • An "Aeon" can present as an elf in Andrus, a long-memory AI on Astraeus or an elder vampire in Hidden World.

The threat tier system, NPC framework, and encounter design structure work identically across every genre, your prep skills compound. The Core Rules make no assumptions about setting, tone, or genre. Those assumptions live in the catalog where they belong.

For the GM

The GM section is a complete adjudication and design toolkit, not a list of suggestions.

Adjudication Framework establishes when to call for a roll, how to set Thresholds, and how to handle outcomes that fall between clean success and failure. The framework is principle-based and fast to apply at the table.

NPC Construction gives you a condensed version of the full character rules tuned for named characters, recurring threats, and supporting cast who need depth without full PC build time.

Threat Tier System defines five categories, Minion, Standard, Elite, Champion, Legendary, each with Health formulas, pool budget ranges, and structural expectations. Minions run on a 3–4D budget. Legendary threats start at 14D+. The stat block template at AX.C.13.03 is the authoritative reference for building any threat in any catalog.

Adventure Design covers scene structure, encounter pacing, resource pressure, and how the rest economy interacts with challenge calibration.

Campaign Structure provides three arc frameworks built on the Core Rules' power level progression, with guidance on when to escalate scope and what that means mechanically for the table.

Genre Catalogs

Catalogs are designed to deliver setting-specific fiction, lineages, power traditions, professions, equipment, threats and factions. Essential mechanics connect directly to the Core Rules.

Who This Is For

  • Players and GMs who are tired of system-hopping. AxiomRPG Core Rules is designed to be a permanent mechanical home, one framework that travels across every genre you want to run. Invest in the system once; spend the rest of your time on the worlds.

  • Groups who want tactical weight without mechanical overhead. The D6 pool, three Attributes, and transparent XP costs keep character sheets readable and decisions meaningful. The Wild Die ensures no roll is routine.

  • GMs building original content or running published catalogs. The GM toolkit, threat tier system, and Odd Talent framework are built for original world design as much as for running catalog material. If you want to write your own setting on the AxiomRPG engine, the Author Guide covers that too.