Castaway Horror; Survival; Dark Fantasy; Old-School Renaissance (OSR); Rules Lite; Resource Management; Exploration-Driven

At-a-glance: MÖRK BORG lineage • d20 mechanics • Classless • Survival-focused • Crafting, exposure, shelter systems • 2-5 players + GM • Low prep • 2-4h sessions

Theme and Setting

Castaway strands players on a mysterious tropical island where shipwrecked souls must fight tooth and nail to survive. The setting draws from survival horror classics like Lost and The Martian, blending tropical paradise with lurking dread. The island is not uninhabited—strange creatures, ancient ruins, and hostile weather conspire against the castaways. Players face the psychological toll of isolation alongside physical threats, creating a tense atmosphere where hope is as scarce as fresh water.

Core Mechanics and Rules

Survival Systems

The game centers on comprehensive survival mechanics covering exposure, shelter building, crafting, hunting, gathering, and debilitating ailments. Players must manage hunger, thirst, temperature, and rest while exploring the harsh environment. An island weather system adds unpredictability, forcing players to adapt plans as storms roll in or droughts persist.

MÖRK BORG Compatibility

Built on the MÖRK BORG third-party license, Castaway uses familiar d20 roll-under mechanics, player-facing rolls, and brutal consequences. Characters are classless, defined by their stats, gear, and the choices they make. The 98-page book includes a menagerie of island creatures, mysterious encounters, and escape plans, providing everything needed to run extended survival campaigns.

Escape and Victory

Unlike traditional dungeon crawls, Castaway offers multiple paths to victory—building rafts, signaling passing ships, or discovering hidden escape routes. This gives players clear goals while maintaining the tension of limited resources and mounting dangers.

What Makes It Unique

Castaway stands out as one of the few TTRPGs to deeply integrate survival mechanics without bogging down play. The exposure and crafting systems are intuitive yet meaningful, creating natural resource tension. Its compatibility with MÖRK BORG means it can be played standalone or integrated into existing campaigns, adding survival horror elements to dark fantasy adventures. The game art and layout maintain the striking visual aesthetic associated with the MÖRK BORG lineage.

Target Audience and Player Experience

Castaway appeals to players who enjoy survival video games like The Long Dark or Subnautica, fans of survival horror media, and groups seeking a change from traditional combat-focused RPGs. The game supports both one-shot sessions and longer campaigns, with procedures that make GM preparation minimal. New players find the survival context intuitive, while experienced GMs appreciate the flexible framework for creating emergent stories of desperation and triumph.