RPG System Guide

Coriolis: The Third Horizon: Dice & Strategy Guide

Arabian-nights science fiction among the stars. Free League’s Coriolis runs on a Year Zero dice pool with a haunting twist: you can pray to the Icons for a second chance, but the darkness is always listening.

Coriolis: The Third Horizon, published by Free League, blends space opera with the culture and mysticism of the Middle East and North Africa. It uses the Year Zero Engine, but its signature is spiritual: when a roll fails, you can turn to the nine Icons for help — and every prayer answered gives the Game Master fuel for the dark forces that stalk the Horizon.

The dice and the core mechanic

Rolls use a pool of six-sided dice assembled from three sources: your attribute, your skill, and any bonus from gear or circumstances. Add them together, roll that many dice, and look for sixes. Each 6 is one success, and a single success is usually enough to accomplish the task — additional sixes give a better, faster or more effective result, and matter especially in combat. Like all Year Zero games, this is a count-the-successes system: you never total the dice, only the 6s count, and a larger pool simply means more chances to land one.

Coriolis groups its skills under a small set of attributes and offers both general and advanced skills, so a capable specialist — a pilot, a negotiator, a gunfighter — brings a satisfyingly fat handful to the things they are built for.

Praying to the Icons and Darkness Points

The mechanic that defines Coriolis is the prayer. If a roll fails, your character can pray to the Icons — the setting’s revered celestial powers — to re-roll dice that did not come up sixes, hoping the heavens grant the success you need. It is the game’s equivalent of a push, but framed as an act of faith rather than reckless strain.

The cost falls not on you but on the world. Every time the players pray, the Game Master gains Darkness Points, a growing pool the GM spends to complicate scenes, empower enemies, and unleash the ominous forces that haunt the Third Horizon. So each re-roll is a bargain: you buy a better chance now, and hand the shadows more power to strike later. The tension between needing the Icons’ help and dreading what that help awakens is the heart of the game’s mood.

How a roll resolves

To make a roll: total your attribute, skill and gear dice, pick up that many six-siders, and throw them. Count the sixes as successes; one is usually enough, more is better. If you fail and the situation allows, you may pray to the Icons to re-roll the non-sixes — and the moment you do, the GM banks Darkness Points. You can normally only pray once per roll, so weigh whether this particular success is worth feeding the dark. Combat, healing and other systems all read the same pool of successes, with extras spent on greater effect.

Effective strategy

  • Pray for the rolls that truly matter. Every prayer hands the GM Darkness Points that will come back to bite the whole group. Save your appeals to the Icons for pivotal, high-stakes moments.
  • Build a fat base pool. The less you need to pray, the fewer Darkness Points you generate. Strong attributes, skills and gear let you succeed cleanly and keep the shadows starved.
  • Spread the specialities. Because pools come from attribute plus skill plus gear, a crew that divides expertise brings big handfuls to the right tasks instead of everyone praying to cover gaps.
  • Think as a group about the darkness. Darkness Points are a shared danger. One player praying constantly endangers everyone, so coordinate who spends faith and when.
  • Spend your extra successes well. In combat and tense scenes, surplus sixes buy real advantages — extra damage, speed or control. Aim for a clean margin, not just a bare pass.

Beginner tips and common mistakes

  • Only sixes count. Don’t add the dice up — count the 6s. One success usually carries the task.
  • Prayer isn’t free. New players re-roll on instinct and flood the GM with Darkness Points. Decide whether the success is worth the future cost first.
  • Darkness comes back around. Those points don’t vanish — they return as complications and threats. Respect the meter you are filling.
  • Lean on your specialities. You succeed cleanly, and pray less, when the right character takes the right roll.
  • Soak up the setting. Coriolis is as much about faith, factions and mystery as gunfire. The prayer mechanic sings when you treat the Icons as real.

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