Sea of Thieves is a first-person action-adventure game developed by Rare and published by Microsoft Studios. In the game, players explore an open world via a pirate ship. The game is described as a "shared world adventure game", which means groups of players will encounter each other regularly during their adventures, sometimes forming alliances, sometimes going head-to-head. The player assumes the role of a pirate who completes voyages from different trading companies in order to become the ultimate pirate legend. Players need to become at least level 50 with 3 of the trading companies to become a Pirate Legend.
The game was first conceptualized in 2014. Rare was inspired by players of PC titles such as Eve Online, DayZ and Rust, who used the tools provided by these games to create their own personal stories.