Obsidian Entertainment has announced that The Outer Worlds 2’s first story DLC, Side Effects Guaranteed, will launch on December 2, 2026, for PlayStation 5, Xbox Series X|S and PC. The $14.99 expansion is the first chapter of a two-part narrative adventure, with its continuation scheduled for spring 2027.
The developer confirmed the release date and new content in announcements published on the official PlayStation Blog and Xbox Wire on November 10. Side Effects Guaranteed introduces a new region, additional quests, five weapons, expanded character progression and decisions that will directly influence the second expansion.
The story begins when the player’s crew aboard the Incognito intercepts a distress signal from a derelict spacecraft. Investigating the vessel reveals crew members placed in suspended animation after exposure to a substance that causes fatal cellular deterioration.
The search for a cure leads to Elysium Valley, a previously unexplored region on Eden. Players become involved in a dispute within Sub Rosa, a criminal organization whose members steal from competing factions. Two of its agents, Gordon Hazen and Algernon Lankester, have conflicting plans for the settlement and the infected crew.
Hazen seeks a solution to save his people, while Lankester wants to exploit the settlement for his own benefit. Players must navigate these competing interests, with their decisions determining the fate of the settlement, the stranded crew and Sub Rosa itself.
Elysium Valley also introduces new facilities, quests and hostile creatures, including vicious canids and primal sprats, which are significantly larger versions of the creatures encountered in the base game.
The expansion raises the maximum character level from 30 to 36, providing additional skill points and allowing players to unlock three more perks. Obsidian is introducing 15 new perks and four flaws that offer new character-building possibilities.
One of the new flaws, Lethally Tolerant, increases a character’s maximum toxicity tolerance but causes instant death if they experience a Toxicity Crash. Another, Must Have Been the Wind, marks an assassination target during combat. Successfully eliminating that target grants a 20% damage and speed bonus for the remainder of the encounter. Attacking the wrong enemy or failing the objective instead applies a 10% damage and speed penalty for 30 seconds.
Combat additions include five new weapons. The Immobilizer can suspend enemies in the air, leaving them vulnerable to follow-up attacks involving other weapons, grenades or Tactical Time Dilation. The 1/6 Resolver delivers an enhanced attack with every sixth bullet fired, potentially complementing builds focused on critical hits.
Other additions include a weapon designed to deal extra damage to creatures, a special Tossball Stick and a plasma weapon. Players will also gain access to new armor, companion outfits and a Sub Rosa-operated radio station featuring 20 new songs.
Obsidian has confirmed that Side Effects Guaranteed takes place shortly before the main campaign’s point of no return. However, players who have already completed the story will not need to replay the entire game to access the expansion.
A new option on the main menu will allow players to begin the DLC directly using a premade level 27 character. Players can allocate skill points and select perks before starting, providing an alternative entry point for returning players.
A separate update arriving alongside the DLC on December 2 will also introduce character respec functionality for all players, allowing them to redistribute their character’s abilities at any time. New custom game settings will additionally let players adjust the number of skill points earned per level.
Side Effects Guaranteed will be available separately for $14.99 or through The Outer Worlds 2 Premium Edition and Premium Edition Upgrade. Obsidian has not announced a specific release date for the second chapter beyond spring 2027.
Unlike a standalone adventure, the two expansions will form a connected storyline. Obsidian has confirmed that choices made during Side Effects Guaranteed will directly affect events in the follow-up DLC, giving players a reason to consider their decisions before the story continues next year.
