The sides still need to work out many details, and a deal could fall through, according to one of these people, who spoke on condition of anonymity.
Acquiring Minecraft would give Microsoft control of an online world that has defied many of the conventions of the modern games business to become a blockbuster success.
Minecraft’s blocky graphics are crude by today’s standards, looking like virtual Lego bricks. But unlike many of the start-ups purchased by big technology companies for billions of dollars, Minecraft is already a lucrative business. This year, Mojang, the privately held Swedish company that makes Minecraft, told The Wall Street Journal that its revenue was about $360 million last year, up 38 percent from the year before. The Journal reported the discussions with Microsoft earlier on Tuesday. Mojang was co-founded by Markus Persson, a 35-year-old programmer and game designer who is better known in the gaming world by his gamer name, Notch. Mr. Persson has said in the past that he did not want to sell the company or take money from outside investors.
In an era when many games, especially for mobile devices, are given away, and derive their profit from the sale of virtual currency and other items, Mojang sells Minecraft the old-fashioned way — by charging people to buy a copy. The price varies depending on what kind of device people use to play the game, ranging from $7 on mobile phones to $27 for computer versions. A version of Minecraft for Microsoft’s Xbox, which has been a top seller for the console, costs $20.