The Big Game (rugby union)

The Big Game is an annual rugby union match hosted by Harlequins during the Christmas holiday season each year. It is one of Harlequins' regular home matches in the Premiership Rugby but it is moved from their usual home ground at the Twickenham Stoop (14,816 capacity) to the much larger Twickenham Stadium (82,000 seats).
There have been other high-profile matches in London between Premiership Rugby clubs at other times, including the London Double Header (2004-2017), Bath's The Clash at Twickenham and Saracens' games at Wembley Stadium, London Stadium and Tottenham Hotspur Stadium. 
Big Game 13.
Pending developments with the COVID-19 pandemic, the Big Game 13 will be held in spring 2021. Further details are due to be announced.