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Overview

Player choice is at the heart of The Expanse: Osiris Reborn. As a studio built on narrative-driven CRPGs like Pathfinder: Wrath of the Righteous and Warhammer 40,000: Rogue Trader, Owlcat Games has a deep track record with branching storylines and meaningful decisions. Osiris Reborn carries that philosophy into its action RPG format. Decisions made early in the campaign ripple throughout the entire experience, affecting companion fates, faction relationships, mission outcomes, and the state of the world around you.

The developers have been direct about what this means in practice: The Expanse universe is cruel, and some characters might die because of your choices. There is companion permadeath. There are no warnings before pivotal decisions. And once a consequence plays out, there is no option to reverse it.

The Etude System

Under the hood, Osiris Reborn tracks player choices and narrative states using what Owlcat calls the "etude system." This is a proprietary tool originally created for the Pathfinder games, where it handled the enormous branching narratives those titles are known for. For Osiris Reborn, the entire system was rebuilt from scratch in Unreal Engine 5, along with the studio's dialogue editor.

The etude system records every decision, conversation outcome, and narrative flag the player triggers. It then references those flags throughout the rest of the game to determine how characters react to you, which dialogue options are available, which missions become accessible, and how story events resolve. This is the technology that allows early-game decisions to have consequences dozens of hours later.

Companion Permadeath

Certain companions can die permanently based on player choices, and once they are gone, they are gone for the rest of the playthrough. The developers have confirmed this system draws direct inspiration from Mass Effect 2's suicide mission, where every squad member's survival depended on the choices the player made throughout the entire game.

Companion permadeath in Osiris Reborn is not limited to a single climactic mission. The risk exists throughout the campaign. Decisions about how you treat your crew, which missions you prioritize, and how you handle critical story moments all feed into whether companions survive. Each companion has their own background, personal struggles, and opinions that influence major plot events. Helping a companion through their personal problems (or ignoring them entirely) can determine their fate later.

Unsignposted Decisions

One of the most striking elements of the choice system is that many important decisions are not flagged or highlighted. There is no on-screen prompt warning you that a conversation option will lock in a major consequence. The game trusts the player to weigh their words and actions the same way they would in a real situation, without the safety net of knowing which choices "matter" and which do not.

This design means that side conversations, seemingly minor mission decisions, and offhand remarks to crew members can carry real weight. The game does not separate "main story decisions" from "side content decisions." Everything feeds into the etude system and can produce consequences down the line.

Faction Alignment

The game's three major factions (Earth, Mars, and the Belt) respond to the player's actions and origin. Choosing an Earther, Martian, or Belter origin during character creation determines your initial reception with each faction. An Earther visiting Ceres will face hostility from Belters. A Belter may find doors open on the Belt's stations that are closed to others.

Faction alignment is not permanent. The developers have confirmed that players can shift their allegiances during the campaign. This opens up paths like becoming a double agent, switching ideological alignment entirely, or playing factions against each other. Your actions, not just your words, determine where each faction stands on you.

The Pinkwater Station Example

The clearest example of the choice system in action comes from the Gamescom 2025 demo, set on Pinkwater Station. During a Protogen attack on the station, the player must decide whether to ask the civilian population to resist or to surrender. If you ask them to stand down, the civilians survive and the station's armory remains stocked, giving you access to much-needed supplies and equipment. If you encourage resistance, groups of civilians are killed, their bodies litter the station corridors, and the armory may be depleted.

This single decision affects the environment you walk through (bodies vs. intact station), the resources available to you (stocked armory vs. empty one), your relationship with the station's population, and potentially your standing with the station's administrator. The developers used this example to illustrate how choices reshape not just the story but the physical world and gameplay resources.

Companion Relationships and Romance

Your relationships with companions develop over time based on your choices and leadership style. Companions are not simple approval meters. Each crew member has their own perspective on events, and during significant story moments they will offer opinions, suggest courses of action, and sometimes provide contacts or support that can change the outcome of a situation.

Romance is confirmed as part of the companion system, though the developers have not specified which companions are romanceable. Creative Director Alexander Mishulin noted that the crew lives together on a small ship for a long time, and the close quarters naturally create interpersonal dynamics. The game follows a character-focused development philosophy the developers have compared to Persona 5, where characters are at the center of the story and evolve throughout the entire experience.

Companion Activity During Missions

Even companions who are not in the player's active two-person squad remain engaged in the story. They contact the player over the radio to give advice, may appear in specific locations during a mission, and can be assigned their own tasks elsewhere. The design ensures that no companion ever feels like they are sitting idle on the Gemini while the player is in the field. Crew members who are not brought on a mission can embark on their own operations, adding a layer of strategic decision-making about how to deploy your team.

Skill Checks

The game includes skill checks in dialogue and exploration that gate optional content. Failed checks do not block the main story, but they can deny access to bonus areas, additional loot, alternate mission approaches, or information that changes how you understand a situation. This means that character build decisions intersect with the choice system: a player who invested in social skills might talk their way past a guard, while a combat-focused player would need to find another route.

Summary of Confirmed Choice Mechanics