While the deal's financial terms were not disclosed, a little bird reportedly familiar with it told Bloomberg that the companies were negotiating a price of over $350 million. Tencent had already invested in Riot in earlier rounds of funding. Riot will remain in its Los Angeles offices, still operating independently with the current management team.

"This is exciting news for 'League of Legends' players and the existing Riot Games team," said Riot CEO Brandon Beck in the announcement. "Tencent's investment will provide our talented team of designers, developers and community staff with additional resources to focus on innovating around 'League of Legends' and launching new projects that push the boundaries in the gaming space."

The DotA-inspired multiplayer, tactical action-RPG League of Legends launched in 2009, with a free client supported by microtransactions for unlocking characters, alternate skins and other goodies which don't unbalance the game.