/Film has a great breakdown of how Marvel Studios does business which is a little atypical of how traditional movie studios sign actors and actresses. Below is a summary of their report.
The Traditional Method
Directors and producers meet with prospective candidates who test for roles and then they meet with agents to hammer out the finer points of a deal. That's pretty much how any contract negotiation process happens no matter what entertainment venue it happens to be.
The Marvel Method
At Marvel Studios, things are a bit different. Before someone can even test for a role they sign a contract which spells out what they're going to make and how many pictures they're signed up for. So all those actors and actresses you hear are up for roles like Star-Lord and Drax, they've already signed a contract with Marvel. The sticking point is that the deal isn't 'active' unless they're ultimately chosen for the role. This is a lot like the contracts TV actors sign during pilot season. Right now, Guardians of the Galaxy is the main Marvel film casting so what's happening is that Marvel already has deals with all the names being mentioned, they simply have to make a selection. This deals are notoriously lowball figures (respectively speaking) and that has led to Jason Momoa deciding that he doesn't want to be Drax the Destroyer after all. What Marvel is banking on is that actors will sign on for the exposure and use their new found fame to land big paydays elsewhere i.e. Chris Hemsworth and Tom Hiddleston. It's why you'll always see unheralded, previously unheard of actors signed up for the roles that require multiple film appearances. This deal structure even (sort of) applies to their big name actors like Robert Downey Jr. but unlike his younger Avengers, Downey's deal is backloaded, meaning he receives a portion of the film's earnings and is how he took home a cool $50 million from The Avengers. And when you hear talk of Downey's contract expiring after Iron Man 3 and his desire for a big payday, he's referring to switching his contract around to a frontloaded structure where he receives his pay upfront, regardless of the film's box office performance. We'll have to wait and see how Kevin Feige and Marvel Studios handle this but I have full confidence that they'll work something out.
