The Outer Worlds 2 gets its first story expansion on December 2. Side Effects Guaranteed costs $14.99 on PC, PS5 and Xbox Series X|S, and it is also included in the game’s Premium Edition and Premium Edition Upgrade. It is the first half of a two-part story; part two follows in spring 2027, according to developer Obsidian Entertainment and publisher Xbox Game Studios.
- Release date: December 2, 2026
- Price: $14.99 (or included with the Premium Edition / Premium Edition Upgrade)
- Platforms: PC, PS5, Xbox Series X|S
- Level cap: raised from 30 to 36
- Part two: spring 2027
Table of Contents
What is the Side Effects Guaranteed story?
Per the Xbox Wire announcement, the DLC begins when you and your crew on the Incognito answer a distress signal from a derelict ship. The crew is in suspended animation after being contaminated during a heist, which left them infected with something that causes what the captain’s video message calls “explosive cell death”.
The trail leads to Gordon Hazen, a Sub Rosa agent, and to Elysium Valley, a new region on Eden with a settlement of forgotten Protectorate subjects. A second Sub Rosa agent, Algernon Lankester, wants your help exploiting those people, so the fate of the settlement, the frozen crew and Sub Rosa itself is up to you. Obsidian says your choices will carry into part two.
Gordon Hazen, the Sub Rosa agent who sends you to Elysium Valley, in an official screenshot. Image: Xbox Game Studios
What is new in the DLC?
Obsidian’s posts on PlayStation Blog and Xbox Wire list these additions:
- New region: Elysium Valley, with its own quests and facilities, plus new threats such as vicious canids and “primal sprats” (regular sprats, but about 100 times bigger).
- Level cap 36: up from 30, with more skill points, three more perk slots and 15 new perks.
- Four new flaws: for example “Lethally Tolerant”, which raises your maximum toxicity but means a Toxicity Crash kills you instantly.
- Five new weapons: including the Immobilizer, which makes targets float, and the 1/6 Resolver, where every sixth shot hits harder. A creature-damage weapon, a Tossball Stick and a plasma weapon round out the list.
- New armor and outfits: including new outfits for each companion.
- A Sub Rosa radio station: 20 new songs.
Combat against one of the DLC's new creature types, from an official screenshot. Image: Xbox Game Studios
How do you start Side Effects Guaranteed?
Obsidian says the DLC’s events trigger right before the point of no return in the main game. There is also a shortcut: when you start a new game from the main menu, you can choose to begin Side Effects Guaranteed directly. That loads a premade level 27 character whose skill and perk points you assign yourself.
Free update for everyone on December 2
A patch lands at the same time as the DLC for all players, whether they buy the expansion or not. It adds a way to respec your character at any time, and a custom game option to change how many skill points you earn per level. Neither Xbox Wire nor PlayStation Blog gives a patch size or full patch notes yet.
Is it on Game Pass?
Neither announcement says whether Side Effects Guaranteed will be included in Game Pass, only the $14.99 price and the Premium Edition bundle. Check the Xbox Wire post or the store page for any change. For the current subscription picture, see our Xbox Game Pass additions guide.
What’s next
The second chapter is slated for spring 2027 with no date yet. Obsidian also develops Grounded 2, covered in our Grounded 2 roadmap, and made Fallout: New Vegas, which our New Vegas console commands guide covers.
Sources: Xbox Wire, PlayStation Blog, Gematsu. Checked November 10, 2026.
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Featured image: Xbox Game Studios
