• Sam Altman has begun his testimony in the civil trial pitting him against AI rival Elon Musk.
• Musk has accused Altman and other OpenAI execs of deceiving him into cofounding the company.
• The trial, now in its third week, could reshape the artificial intelligence landscape.

OpenAI CEO Sam Altman on Tuesday testified that Elon Musk wanted "total control" of the ChatGPT maker — even saying he thought the AI startup should be passed on to his children.

While on the witness stand, Altman described a "particularly hair-raising moment" when his OpenAI cofounders asked Musk, also a cofounder of the company, "If you have control what happens when you die?"

Musk responded, according to Altman, "I haven't thought about it a ton, but, you know, maybe it should just, the control should pass to my children."

Altman told the nine-person federal California jury that he "didn't feel comfortable with that."

Altman's testimony marked a pivotal point in the civil trial of Musk's lawsuit against his AI rival and OpenAI, the company the pair founded together in 2015.

Musk, who testified in the trial last month as the first witness, accused Altman and other OpenAI executives of stealing the "charity" they started.

"Essentially, they're trying to steal a charity, and we're trying to stop them," Musk told the jury.

Musk, who left the firm in 2018, has alleged that he poured tens of millions into OpenAI to support its founding mission as a nonprofit dedicated to developing AI for the public's benefit, only for that mission to later be, in part, abandoned through the firm's partnership with Microsoft, also named as a defendant in his lawsuit.

The outcome of the trial, now in its third week, could reshape the artificial intelligence landscape and cost OpenAI and its backer, Microsoft, billions in damages if Musk prevails.

Altman's testimony follows a roster of other tech heavyweights — including OpenAI president and cofounder Greg Brockman and Microsoft CEO Satya Nadella — who have already testified before the Oakland jury.

In an X post ahead of jury selection in the case, OpenAI said Musk's case "has always been a baseless and jealous bid to derail a competitor."