Robert Downey, Jr. has helped raise more than $2 million for a U.K. hospice by offering fans the chance to join him on the red carpet at the upcoming The Avengers: Age Of Ultron premiere in Los Angeles.

The Iron Man star raffled off a once-in-a-lifetime date in return for a $10 donation to help fund a new Julia's House facility in Wiltshire, England.

The name of each fan who donated will be placed in a grand prize draw and the lucky winner and a friend will receive an all-expenses-paid trip to Los Angeles, a gown or tux fitting and a helicopter ride.

In a video launching the initiative, the actor said, "Have you had the best night of your life on earth ever yet? Well you could, with me, for a good cause. Here's the deal - you donate $10 or more for a chance to win the RJD experience. I correspondingly fly you and a friend to L.A., put you up in a five-star hotel and proceed to awesome the crap out of you.

"I'll take you indoor skydiving, on a helicopter tour, a pit stop at Randy's Donuts and after riding your sugar high all the way to a fitting for a tux or gown, we are going to meet up for a bit of pre-premiere caviar.

"We'll giggle, chat, take pictures, and perhaps even engage in a battle of wits... And then, right before sunset, we make a grand entrance at the venue on the red carpet, and then you become one of the first people on earth to see Avengers: Age of Ultron.

"All proceeds go towards funding Julia's House. This place is amazing. It's a hospice for children with terminal illnesses. It's a win-win."

Downey, Jr. has ties to the hospice - one of the leading Julia's House patrons is the actor's Sherlock Holmes director, Guy Ritchie.