Los Angeles - The annual gaming convention E3 is traditionally where major video game makers preview their biggest, shiniest new games.
But at Microsoft's press conference on Monday morning in Los Angeles, the house came down when Mr Phil Spencer, head of Xbox, said gamers would be able to use the company's newest consoles to play older games.
So-called backwards compatibility is something console gamers have been asking for since before Microsoft and Sony released new versions of their consoles in 2013. Backwards compatibility is desirable, when titles typically retail for about US$60 (S$81). Neither company has really offered it, although Sony has allowed players to stream older games for a fee through its PlayStation Now service.
Mr Spencer was barely able to get the announcement out on Monday.
The applause erupted once it became clear what he was getting at. The first batch, which will include 100 games, will be available by the end of the year, with more coming next year, Microsoft said.
Unlike Sony's streaming service, Microsoft's will allow people to play games they had purchased for their old consoles without having to pay a second time. Those playing Xbox 360 games on their Xbox Ones will be able to use features that are available only on the newer machines, such as screen shots and live streaming.
Microsoft could use this boost. It has been lagging behind Sony, and market researcher IHS predicts there will be 34 million PlayStation 4s sold by the end of this year, compared with just 20 million Xbox Ones. The easiest way for a console company to differentiate itself is to offer games that are available only on its platform.
Microsoft is looking to gain some ground on this front this year. The Xbox event at E3 started with a demo of the new version of Halo, the console's biggest title, which will be available this autumn, and also included new versions of exclusive games such as Forza Motorsport 6 and Rise Of The Tomb Raider. Sony has said its own line-up of exclusive games will be relatively thin this year.
But Microsoft already has plenty of titles that can be played only on Xboxes: the games its customers have already purchased. Making those available on the newer console is unlikely to attract PlayStation users to switch, as they probably do not have a living room full of old Xbox discs. But it is a clever move to shore up Microsoft's base of customers, many of whom may be tempted to give the other side a try.
Bloomberg, Agence France-Presse