The wait is finally over for survivors of Nalcott. Once Human: Isles of Abyss, the game’s largest expansion to date, has officially launched worldwide, taking the fight against the Stardust to the open ocean. Whether you’re a seasoned veteran or a newcomer drawn in by the promise of naval warfare and deep-sea horror, here is everything you need to know before setting sail.
🌊 The Launch: A New Ocean Awaits
Isles of Abyss is a free update that arrived on October 22, 2026 (October 21 PT), simultaneously across PC, PlayStation 5, Xbox Series X/S, and mobile devices. The best part for multiplatform players? It features full cross-play and cross-progression, meaning your save and your friends travel with you regardless of the screen you choose. If you’re an Xbox Game Pass subscriber, you can dive in immediately without any extra cost.
🚢 A Completely New Survival Scenario
Unlike previous updates, Isles of Abyss introduces a separate scenario with its own unique progression loop, rather than just adding a new map to the existing game. The core experience is divided into two distinct phases, each lasting a specific duration:
Phase 1 (5–10 days): This is your preparation window. The duration can shrink if the community progresses quickly. Use this time to build your ship and stockpile resources.
Phase 2 (11 days): The stakes rise. The server’s purification progress culminates in an endgame challenge against the expansion’s signature boss, The Sunken Lord. Phase 2 also introduces tougher enemies, like larger Voyager ships, and exclusive ship cannons.
After the cycle ends, the scenario resets, giving you and your crew a fresh start to try new strategies.
⚓ What’s New: Ships, Diving, and Hostile Waters
The expansion fundamentally changes how you survive by introducing a Land-Sea Dual Survival Loop spanning three connected layers: the sea surface, islands, and the underwater depths.
Your Ship Is Your Castle
Naval base-building is the centerpiece. You start with a small skiff and can upgrade it into a massive Mobile Sea Fortress that functions as your base, workshop, and artillery platform. Customization is deep, allowing you to modify the hull, gunwale, bow, deck, and more, with the ability to save multiple ship designs for different tactical approaches.
The Depths Beckon
Exploration isn’t limited to the surface. You can dive underwater to find buried treasures and aquatic resources. This requires specific gear, such as a suit that resists ocean contamination and a shark diving suit for faster swimming. Monitoring your oxygen level is crucial, though an auto-activating tank provides a safety net.
Haywire Zones: The Weather Is Against You
The archipelago is plagued by Haywire Zones—random environmental crises that can disrupt visibility, sanity, temperature, and supply consumption. However, these zones also yield special resources, making them worth the risk. The map shows icons with timers for active and upcoming zones, giving you a window to prepare or avoid them.
👁️ The Threat: The Sunken Lord and the Six Rules
The ocean in Isles of Abyss is not just a place; it is a living, hostile entity known as The Sunken Lord. An enigmatic navigator named Malla, who has “drowned a thousand times,” warns of six critical rules for survival. These rules hint at the expansion’s unique hazards, including predatory lighthouses and disguised, living islands that prey on unwary sailors. The ultimate test is a community-unlocked boss fight against The Sunken Lord itself, which promises substantial rewards for those who dare to challenge it.
💎 Once Human: Isles of Abyss
isn’t just a map expansion; it’s a reinvention of the survival formula. By shifting the focus from a contaminated landmass to a vast, conscious ocean, Starry Studio has created an experience that feels like a blend of Sea of Thieves‘ naval adventure and Subnautica‘s underwater tension. The emphasis on customizable mobile bases and a two-phase community-driven scenario gives players a powerful sense of ownership and shared purpose.
For veterans, it’s a chance to master a completely new set of mechanics. For newcomers, it’s a massive, free content drop that offers a self-contained survival adventure. The sea is calling, and it is hungry.
