As Epic’s antitrust trial against Google continues, the former’s CEO Tim Sweeney has revealed the campaign to open PlayStation to cross-play could have led to legal action.

Epic Games was one of many developers calling for Sony to enable gamers to play multiplayer matches against people on other platforms, with other advocates include the teams behind Rocket League and Ark: Survival Evolved.

Sony repeatedly shot down this suggestion but finally relented in September 2018.

With open platforms being a key discussion point of the Epic vs Google trial, a San Francisco courthouse heard on Monday heard how far the Fortnite firm planned to go to support the push for cross-play, The Verge reported.

“We were willing to fight them in court if necessary,” Epic CEO Tim Sweeney said during his time on the witness stand.

The conversation revolved around a June 2018 email Sweeney sent to Phil Rosenberg, then PlayStation’s senior vice president and head of global publisher and developer relations.

The email read: “Please inform Kodera-san, and please be clear, that Epic will enable full interoperability between all platforms in Fortnite at a timely point in the future … we are prepared to pursue this course with all available resources, wherever it leads us, and for however long.”

After this discussion, the court proceedings moved on with Sweeney noting that Sony and Epic have worked much closer together since then. For example, Sony Music has partnered on Fortnite events, Sony Pictures uses the Unreal Engine for some of its productions, and Sony Corporation has become a shareholder in Epic Games.

On the subject of shareholders, Sweeney was questioned about the role China-based Tencent plays in Epic’s business – a subject Judge James Donato ordered Google to only bring up once during the trial.

When later asked by Epic’s lawyer whether Tencent controls Epic, Sweeney replied: “No… I do. I’m the controlling shareholder of Epic.”

The Epic CEO was also asked about Tencent’s reaction to Project Liberty, to which he said: “I came up with the idea of Project Liberty, and when we disclosed to them, they were rather surprised.”

Project Liberty, as revealed during the Epic vs Apple trial two years ago, was Epic’s ‘battle plan’ to add direct payment options into Fortnite, avoiding Google and Apple’s 30% cut and prompting the game to be removed from app stores – to which Epic responded with these lawsuits.

Sweeney admitted to this plan when questioned by Google’s lawyer.

Outside of Sweeney’s time on the stand, perhaps the most notable revelation from Monday’s proceedings was more details on Google’s plan to invest in or acquire Epic Games – something that first emerged from court documents ahead of this trial in 2021.

Referred to as ‘Project Elektra,’ The Verge reported the court was show an email from Phil Harrison, who heads up Google’s games initiatives, on July 15, 2018 listing the “strategic rationale” for investing in the Fortnite firm.

Among his reasons, he said that Fortnite could be “the leading business driver for Google” across YouTube, Google Cloud Platform, and Project Yeti (which was later unveiled as short-lived streaming service Google Stadia).

Another email from Google director Dave Sobota referred to Harrison’s proposal that the company either buy Epic’s shares from Tencent “to get more control over Epic,” or team up with Tencent to buy 100% of the Fortnite firm.

The trial continues later today, and you can follow the biggest news via the ‘Epic vs Google‘ tag.