Details on Riot Games' second videogame have surfaced after the company's CEO — Marc Merrill — had his Twitter account hacked. The hacker, referring to himself as 'Jason,' used Merrill's account to release images from what he termed "Riot's card game." They show a login screen for something titled League of Legends: Supremacy, and a set of card templates that suggest the unannounced game is a trading card game in the mold of Magic: The Gathering, or Mojang's Scrolls.

'Supremacy' is apparently a standalone game

League of Legends: Supremacy was registered as a trademark in 2012. Some speculated it would be a new mode for League of Legends proper, but the hacker used Merrill's Twitter account to claim that Supremacy was "a standalone game" - a game for which he had the "server and client source." The hacker also said that Supremacy was "fully completed, but never released," and that he would release a 220MB file containing all of the game's artwork unless Merrill contacted him directly.

CEO Marc Merrill said the images were from "one of many" game prototypes

'Jason' didn't follow through on his threat, instead handing Merrill's Twitter account back to the rightful owner. Merrill himself then confirmed that his account had indeed been hacked, but that Supremacy shots leaked were "old screens from one of the many prototypes" Riot had experimented with.

It's not clear where the hacker originally obtained the leaked images, either through Merrill's Twitter direct messages, or from another source. This is not the first time Riot has been exposed by hacks: in 2012, League of Legends' European server was breached and passwords leaked. In August of this year, the same happened to the North American server.

League of Legends has a vast fanbase — more than 12 million people play the game daily — but until now Riot has been silent on its upcoming plans. Although Merrill didn't confirm whether Supremacy would ever see release, its leak shows that the developer is looking beyond its work maintaining one of the world's most popular games.