Ethan Crossfield 
If you enjoy Sea of Thieves for its open-sea pirate sandbox, Season 20 is aiming straight at the part you can’t always control: the types of games you play. On June 18, Rare’s free Custom Seas update will let players create and share their own modes and experiences—ranging from PvP formats to custom spawns and cinematic tools—though not everyone is convinced the approach matches community wishes.
What’s changing in Season 20: Custom Seas becomes the headline feature
Sea of Thieves has used a seasonal model since 2021, steadily adding new content for players to chase. Season 20 arrives on June 18 with Rare’s biggest free update in years, centered on Custom Seas—an in-game system that shifts creative control toward players.
Instead of only choosing from pre-made playlists, Custom Seas is designed to let players build new game modes and experiences and then share them with friends and others. The idea is to turn the game’s pirate fantasy into a platform for user-made rulesets and scenarios, supported by tools that go beyond basic customization.
During a newly released trailer tied to the 2026 Xbox Games Showcase, Rare previewed multiple PvP-style concepts. These include Rowboat Royale, a format built around six-player cannon rowboats where survival is the objective; a team deathmatch concept using flame cannons; and a King of the Hill-style mode. The trailer also pointed to Hide & Seek and Rowboat Racing as additional examples of what creators could craft.
Custom Seas isn’t limited to competitive play, either. The update also supports spawning a wide range of assets available in the game—such as NPCs, creatures, and treasure—so creators can build encounters and progression scenarios for more player-versus-environment experiences. Enhanced camera tools are also part of the pitch, with the trailer teasing cinematic angles and a distinct visual style (including what appears to be a tilt-shift-like perspective).
Who’s affected: creators get tools, everyone gets more variety
Custom Seas is aimed at two groups at once. First are players who want to design their own experiences—people who look at Sea of Thieves and see raw materials (boats, combat options, assets, and camera tools) that could be organized into something new. For them, the update offers more than just cosmetic freedom; it’s about authoring modes, spawns, and moments.
Second are players who simply want more to do. By enabling sharing, Rare is effectively betting that community-made modes will expand the game’s variety without waiting for every idea to be greenlit as official content. That matters because Sea of Thieves’ history includes a rocky start, with early server outages, game-breaking issues, and a shortage of content at launch. Over time, ongoing updates and quality-of-life improvements helped the game recover into a live-service success.
Still, the community reaction appears split. Some players are frustrated that Rare is prioritizing player-made content rather than directly implementing what they believe the community is asking for. Others see Custom Seas as a path to the PvE experience they want—especially since the existing Safer Seas option can be restrictive and limiting. There’s also a third camp: players who are simply excited to build and share their own creations.
What comes next: watch for Custom Seas modes and the tools behind them
With Season 20 landing June 18, the practical question for players is how quickly Custom Seas content will show up and how diverse it will become. The trailer’s examples—PvP formats like Rowboat Royale and team deathmatch, plus Hide & Seek and racing—suggest Rare expects creators to experiment with both competitive and casual structures.
But the bigger long-term lever is the broader spawning capability: creators can place NPCs, creatures, and treasure, then shape how encounters unfold. Combined with enhanced camera tools and the ability to create social spaces, Custom Seas could turn Sea of Thieves into something closer to a shared creative hub, not just a fixed set of adventures.
For players deciding whether to follow, play, or wait, the safest approach is to treat June 18 as the start of a new content ecosystem. If you like trying new modes, expect a wave of early community experiments. If you’re primarily looking for a specific PvE direction, Custom Seas may be worth watching—especially given the complaints that Safer Seas doesn’t always go far enough.
What players should know
- Custom Seas is a free update tied to Sea of Thieves Season 20, arriving on June 18.
- It lets players create and share new game modes and experiences with friends and others.
- PvP examples shown include Rowboat Royale, flame-cannon team deathmatch, and a King of the Hill-style mode, plus Hide & Seek and Rowboat Racing.
- Creators can spawn assets such as NPCs, creatures, and treasure, and use enhanced camera tools for cinematic moments.
- Community reaction is mixed: some want Rare to focus more on community-requested changes, while others hope Custom Seas enables more flexible PvE play.
Expert View
Custom Seas is a smart bet for Sea of Thieves because it targets the one constraint live-service games can’t fully solve: variety. By giving players tools to build modes, spawn encounters, and craft presentation, Rare can generate content momentum that official updates alone might not match. The risk is that players who want specific PvE improvements may feel sidelined at first. Overall, Season 20 looks like a meaningful pivot toward community-driven structure—one that will be judged quickly by how compelling and accessible the first shared modes become.
