Rare's used Microsoft's E3 press conference to announce a brand new title: Sea of Thieves.
The game's a pirate-themed first-person adventure that was demoed via a gameplay trailer. It's got the colourful touch of Rare's previous titles, and there seems to be a multiplayer component, allowing you to explore islands with friends, sail your ship (and clash with other ships) and more.
We'll have more news on the game shortly.