Sea of Thieves: Cursed Sails brings alliances and the undead at the end of July

Sea of Thieves will get more dangerous, and more social, when the free Cursed Sails update arrives on July 31. Developer Rare said the update will "change things forever" by adding literal skeleton crews to the high seas, and a new alliance system that will make it easier to take them on. 

"The sails you see cresting the horizon are no longer guaranteed to be other players making their own way through the world. The decks beneath those masts may now be manned by skeletal marauders returned to the seas from their restless graves," Rare wrote. "All that sustains these grinning terrors is a thirst for battle that leads them to terrorise Outposts and call out defenders to face them on the tides..." 

That's definitely a problem. The upside is that players will have the option to band together to take on stiffer challenges, and enjoy (and, yes, share) the increased loot that results. There's also a new ship on the way, the Brigantine, a type of square-rigged two-master known for speed and maneuverability—and in game terms, designed specifically to be handled by a crew of three. 

Cursed Sails is a time-limited campaign, but the skeleton sailors are not: Rare confirmed that they'll remain in the game even after the event itself is over. But it's the addition of formalized alliances that's the big hook. Players will signal alliance offers, acceptance, and memberships with special pennants, share quests and rewards, and apparently have the opportunity to hose their erstwhile partners, too. 

"For me it's about the stories that this feature is going to enable players to tell," Windows 10 design lead Ted Timmins said in the video below. "Whether they had an armada, and it was six ships sailing around dominating everyone, or it was two, and there was an uneasy alliance, and there was a mutiny, and then the Kraken appeared—it's one of these systems that, when we implement it, it's going to take advantage of every existing system in the game. And how they interplay and intertwine is going to be such a huge part of that storytelling." 

Rare also posted a new Sea of Thieves developer update that you can dive into below: