Elon Musk and Sam Altman are heading into a courtroom battle that could shape the future of OpenAI, the company they helped found more than a decade ago. Jury selection began on Monday, with opening arguments expected on Tuesday in a federal court case that centres on whether OpenAI abandoned its original nonprofit mission in favour of profit and power.

Musk argues that Altman, OpenAI president Greg Brockman and Microsoft enriched themselves by steering the company away from its founding promise to develop AI for the benefit of humanity. OpenAI rejects that claim and says Musk is trying to damage a rival while advancing the interests of his own AI company, xAI.

Billions of dollars and control are at stake

The case is not just about reputation. Musk is seeking damages reported at as much as $134 billion and wants Altman and Brockman removed from leadership. He is also trying to unwind OpenAI’s for-profit restructuring, a move that could hit the company at a critical time as it remains one of the most valuable players in the global AI race. Any ruling that disrupts OpenAI’s leadership or corporate structure could send shockwaves through the global AI industry, with Microsoft’s investment and the company’s market position both in play.

That makes this far more than a founder feud. Any ruling that destabilises OpenAI’s leadership or structure could ripple across the tech sector, especially with Microsoft holding a reported 27% stake in the company and rivals watching closely for weakness.

Case narrows as court battle begins

The trial has been split into two phases. The first will focus on whether Musk’s allegations against OpenAI, Altman, Brockman and Microsoft hold up. The second would deal with remedies if he wins. According to recent reporting, the claims going before the jury now focus on breach of charitable trust and unjust enrichment after other claims were dismissed, dropped, or delayed.

Both Musk and Altman are expected to testify, alongside possible witnesses including Microsoft chief executive Satya Nadella and former OpenAI leaders. The legal clash will reopen old wounds over Musk’s 2018 departure, OpenAI’s later Microsoft-backed expansion, and the brief 2023 removal of Altman that nearly pushed the company into chaos.

OpenAI faces a defining moment

Legal experts say the stakes are enormous. If Musk succeeds on any major remedy, the result could be deeply disruptive for OpenAI at a time when competition in artificial intelligence is intensifying fast. Even if OpenAI prevails, the three-week trial is expected to drag private messages, boardroom decisions and years of bad blood into public view.

For now, the courtroom showdown is about more than two billionaire tech rivals. It is about who gets to define OpenAI’s mission, who controls one of the world’s most powerful AI companies, and whether its nonprofit origins still matter in an industry driven by money, scale and speed.