The Avengers Are Buying America Free Starbucks Coffee

Those cinematic superheroes, Marvel's Avengers, are soaring into the real world and buying free Starbucks coffee. Kind of. Robert Downey Jr., who plays Iron Man, has joined co-star Mark Ruffalo in his #PayItForward coffee challenge. And you can help, too.

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On Dec. 19, Ruffalo, who plays The Hulk/Dr. Bruce Banner in Marvel's Avengers movies, tweeted out an image of a Starbucks gift card with $100 loaded on to it. He encouraged people to use the gift card's bar code to buy themselves a drink, then load more money onto the card (or a fresh one) and pass it along.

And Ruffalo also called out some of his super-powered friends, including fellow Avengers co-stars Downey, Chris Evans (Captain America), and Tom Holland (Spider-Man).

Not to be outdone, on Dec. 22, Downey jumped on the bandwagon by tweeting out his own $100 Starbucks card donation.

And somehow Holland managed to be just as adorably klutzy as the teenage Spidey he plays, asking Ruffalo to show him how to add to the card.

Non-celeb fans were jumping on the free caffeine gift train too, adding anywhere from $5 to $50 and even more to the card to keep the good feelings going and the coffee flowing. While you're out getting coffee anyway, here are a batch of Starbucks secret menu items and how to order them like a pro.