Two Mar de Oro flying sailing ships above an inhabited Golden Sea harbour city.

System-Neutral Setting

A System-Neutral TTRPG Setting

A complete world for the ruleset your table already knows.

The world is authored. The math is not.

Explore how it worksChoose a ruleset

Mar de Oro is a free, system-neutral tabletop roleplaying setting built so the world does not depend on one rules engine. Its factions, history, technology, ships, Fortera, creatures, conflicts, locations, and campaign pressures remain the same whether a table uses Fifth Edition, Pathfinder First Edition, Pathfinder 2e Remastered, Forged in the Dark, another ruleset, or the optional 2d6 Resolution Bridge.

A chosen ruleset determines how uncertainty, damage, advancement, proficiency, vehicles, and similar mechanics are resolved. Mar de Oro supplies the setting, fictional stakes, consequences, and structures those mechanics describe.

What does system-neutral mean?

Mar de Oro separates setting canon from resolution mechanics. The world is written to stay true regardless of which dice procedure a table uses to find out what happens next.

The setting defines

  • places and locations
  • factions and their goals
  • history and the eras after the Sundering
  • peoples and institutions
  • technology
  • ships and airships
  • firearms in the fiction
  • Fortera
  • Éterlumin
  • creatures and phenomena
  • political conflicts
  • campaign pressures
  • consequences
  • adventures

The selected rules engine defines

  • action resolution
  • numerical damage
  • proficiency
  • advancement
  • encounter math
  • vehicle statistics
  • class and resource mechanics
  • spell or ability implementation

Changing rules engines should not require rewriting the world.

System-neutral does not mean play-neutral. Mar de Oro has a consistent approach to information, factions, pressure, choice, and consequence even when the rules engine changes. See How Mar de Oro Plays for the full framework.

How do you know a setting is actually system-neutral?

The useful test is practical rather than promotional. A setting can be written so closely around one game’s level curve, damage scale, or class list that swapping engines means rewriting the world itself. A system-neutral setting keeps the world standing while the resolution engine changes.

Changing rules engines should not require rewriting any of the following:

  • faction goals
  • political relationships
  • geography
  • peoples and institutions
  • technological capabilities
  • what ships can fictionally accomplish
  • what the world's mysteries are
  • what consequences mean

Numerical implementation may change. Canon should not have to. Mar de Oro is designed around that separation.

The setting does not depend on one kind of stat block

The canonical world is not defined by one system’s Armor Class, hit points, challenge ratings, spell levels, proficiency bonuses, or equivalent statistics. Conversion layers provide those mechanics when a table wants them.

Each published conversion pack contains real, system-specific rules for the group that chose it, expressed in the vocabulary that engine already uses.

The first-party option: Tales of Mar de Oro: Native Rules

Mar de Oro also has its own complete rules engine, written for this setting: Capability, Risk and Effect, Callings, Strengths, Techniques, Fortera, ships, battlefield scale, and threats. It is not a conversion and it is not required. The setting remains system-neutral, and the optional 2d6 Resolution Bridge stays the ultralight standalone method.

Open the Native Rules

Use the ruleset your table already knows

Complete free conversion packs are currently published for four systems. Each page below is the canonical destination for that ruleset.

  • Fifth Edition

    Use familiar character and encounter rules with dedicated Mar de Oro procedures for firearms, massed combat, artillery, airships, Fortera, creatures, and high-level play.

    Open the Fifth Edition conversion

  • Pathfinder First Edition

    Use Pathfinder First Edition's native firearms, siege engines, vehicles, and mass combat rules so Mar de Oro battles, batteries, and airships run on structures the system already provides.

    Open the Pathfinder First Edition conversion

  • Pathfinder 2e Remastered

    Keep Pathfinder's native action economy, proficiency, firearms, vehicles, siege weapons, troops, hazards, and encounter structure, with Mar de Oro mechanics layered where the setting needs them.

    Open the Pathfinder 2e Remastered conversion

  • Forged in the Dark

    Run crews, privateers, smugglers, agents, faction pressure, downtime, naval conflict, and dangerous operations through the familiar Forged structure.

    Open the Forged in the Dark conversion

Already using another ruleset?

The System-Neutral Adaptation is the cross-system framework. It covers scale, vessel tracks, capability translation, extended challenges, consequences, and table procedures, so a group can express Mar de Oro through whatever engine it already plays. This page explains why the architecture works; the adaptation chapters carry the actual procedure.

Read the System-Neutral Adaptation

Don’t want another rulebook?

The optional 2d6 Resolution Bridge provides a lightweight standalone method for resolving uncertainty when a group does not want to bring another rules engine to the table. The setting itself remains unchanged.

Open the 2d6 Resolution Bridge

A setting you can actually run

System-neutral does not mean the game master has to invent the world. Mar de Oro supplies locations, factions, adventures, people, ships, rumours, encounters, campaign pressures, history, and GM procedures independently of the chosen rules engine.