Revision 3

Combat and Gameplay

The Expanse: Osiris Reborn is a third-person action RPG built around three interlocking combat layers: cover-based shooting, skills and technology, and companion commands. The developers have cited Gears of War, Mass Effect, The Division, and Uncharted as direct influences on the combat design. Every encounter is meant to feel like a tactical puzzle where positioning, ability usage, and squad coordination all matter. The studio spent nearly a year prototyping the combat before committing to the final model, building and discarding six separate prototypes during pre-production.

Cover-Based Shooting and Time-to-Death

The foundation of combat is a cover system that lets players snap to walls, crates, barricades, and other objects scattered throughout the environment. Leaning out of cover to fire, blind-firing over obstacles, and vaulting between cover points are all standard actions. The system functions similarly to what you would expect from The Division or Gears of War, with the camera pulling in tighter when the player is behind cover and opening up when they move into the open.

What sets Osiris Reborn's cover system apart is the time-to-death mechanic. Exposure outside of cover is lethal on a very short timer. The game is balanced so that standing in the open for more than a few seconds will kill the player on Normal difficulty or higher. Health regenerates when in cover, but this creates a tension: staying behind one piece of cover too long invites flanking, and flanking enemies will force the player out of safety. The push-and-pull between regeneration in cover and the constant threat of being outmaneuvered drives the combat rhythm.

Weapons

The game features a couple dozen weapons spread across several categories, including assault rifles, shotguns, pistols, sniper rifles, and heavy weapons. Each weapon has distinct fire rate, damage output, accuracy, and handling stats. Every weapon also has a secondary fire mode: an assault rifle might mount a grenade launcher, a pistol might switch to a charged shot, or a sniper rifle might have an armor-piercing toggle. Swapping between fire modes is instant during combat.

There are no melee-focused builds in the game. The Expanse setting dictates that close-quarters combat uses shotguns, defensive stances, and point-blank tech abilities rather than blades or fists. If enemies get too close, the player's options are a shotgun blast, a grenade at their feet, or a quick dodge to create distance. The developers wanted combat to feel grounded in the reality of a universe where people fight with guns, armor, and technology, not swords.

There are no silent takedowns either. The game does not feature stealth as a primary mechanic. While the player can sometimes approach encounters from a favorable angle or use the Tactical Visor to scout ahead, combat is the expected resolution for hostile encounters. This design choice keeps the pacing aggressive and prevents the game from turning into a stealth-action hybrid.

Confirmed Weapon Categories

The closed beta build confirmed the following weapon categories available to players. Each category handles differently in terms of range, recoil, and effectiveness in zero-gravity environments.

In addition to standard firearms, vision modes and armor-piercing ammunition are confirmed as tactical resources that enhance the gunplay. Vision modes allow players to detect enemies through obstacles and in low-visibility conditions. Armor-piercing rounds provide an answer to heavily shielded enemies without requiring the player to switch to a heavier weapon class.

Skills and Technology

Beyond raw gunplay, players have access to a range of skills and tech devices that add tactical depth. These are not magic spells dressed up in sci-fi clothing. They are grounded in the technology of The Expanse universe, keeping things plausible even when the action gets intense.

These abilities are tied to the character progression system rather than a fixed class. Players choose which tech to invest in as they level up, and nothing stops a player from mixing shield abilities with shoulder cannons or combining drones with grenades.

Combat Opportunities and Companion Commands

The third layer of combat involves issuing orders to companions. Up to two companions accompany the player in the field at any time. Each companion has their own combat specialty, equipment, and abilities that the player can direct during fights. Ordering a companion to focus fire on a specific target, hold a position, or deploy their unique ability at a key moment can turn the tide of a difficult encounter.

Companion commands create what the developers call "combat opportunities." These are moments where companion abilities exploit structural weaknesses in the environment or enemy positioning. For example, J uses explosives to destroy sections of cover, exposing enemies who were hiding behind it. Ordering J to blow apart a barricade while lining up a shot on the enemies behind it is a basic combat opportunity. More advanced opportunities chain multiple companion abilities together with the player's own tech for devastating results.

Destructible Environments

Environments in Osiris Reborn are partially destructible. Cover can be broken by sustained fire or explosions, forcing players to constantly reposition. Panels fly off walls, ceilings collapse in targeted sections, and debris scatters across the floor. In zero-gravity sections, destruction takes on an extra dimension because loose debris floats freely and can obscure sightlines or create improvised cover. Explosive barrels and pressurized containers can be detonated to deal area damage. The Gamescom 2025 demo showed this system in action, with journalists noting how thoroughly an environment could be torn apart during an extended fight.

Skill Checks

Outside of combat, the game features skill checks during dialogue and exploration. Three skill categories govern these checks: Persuasion, Science, and Hacking. Each has multiple proficiency levels that the player invests in through the progression system. Skill checks are flat pass/fail based on proficiency level, not random dice rolls. If the player has enough points in Science, the check passes every time. If they do not, it fails every time. There is no RNG involved.

Failed skill checks do not block the main story. They close off specific dialogue options, bonus rewards, or optional paths through a scenario, but the player can always continue. This design ensures that no build is locked out of completing the game while still rewarding investment in non-combat skills.

Consumables and Crafting

Consumable items (med-kits, stims, grenades, and similar supplies) are designed to be used frequently rather than hoarded. The game economy provides enough consumables that players should not feel the need to save them for emergencies. The developers want every fight to feel like an opportunity to use the full toolkit.

A crafting system allows players to build weapons, armor, and gadgets from materials found through looting and purchased from vendors. The crafting system was described as "in progress" during the Gamescom 2025 demo, so the final scope and complexity are not fully confirmed. What is known is that materials come from two sources: looting them from environments and enemies during missions, and buying them from vendors at social hubs. The crafting system is intended to complement the loot and vendor economy, not replace it.

No Survival Mechanics

Despite being set in the hostile vacuum of space, Osiris Reborn is not a survival game. There are no oxygen meters, hunger bars, or temperature gauges to manage. The developers made this decision deliberately to keep the focus on combat, story, and exploration rather than resource management. When the player is in a vacuum environment, the danger comes from enemy fire and physics mishaps, not from slowly running out of air.

Fall Damage

Fall damage exists in gravity environments. Jumping or falling from heights in pressurized stations or planetary surfaces deals damage proportional to the distance. In zero-gravity sections, fall damage does not apply (since there is no "down"), but colliding with surfaces at high speed after a botched thrust maneuver can still hurt.

Difficulty Settings

Design Inspirations

The developers have been transparent about the games that influenced Osiris Reborn's combat and gameplay design. Each inspiration informed a specific aspect of the experience.

There are no traditional classes in the game. Players build custom playstyles through weapon discovery, ability combinations, and synergy-building with their companions. This classless approach means the game never forces players into a predetermined role. Early hours offer freedom to experiment, and over time the player naturally gravitates toward a build that suits their preferences.

Design Philosophy

Owlcat has described the overall design philosophy as wanting combat to feel like an action movie set in The Expanse universe. Every firefight should be kinetic, with the player constantly moving between cover, issuing companion orders, and deploying abilities. The combination of grounded, physics-based weapons and high-tech devices creates a push-and-pull where players need to balance aggression with caution. Rushing into the open without a plan will get you killed, but staying behind one piece of cover for too long means it will eventually get destroyed or you will get flanked.