There are a large number of characters- choose one to be your expedition leader (this gives a unique bonus) and then two to be expedition members. Each character has one of a number of skills and abilities, and also approaches. Central to the RE experience is the idea of attitudes; that is, the effect of your actions on your opponents. Your attitude can be Friendly, Devious, or Aggressive, and so can your opponent. Each adventurer has three moves (and gains more); one each of Aggressive, Devious, and Friendly. Also important are moods and spirit- a mood can be either negative or positive. Whether it's negative or positive matters for the moods that can be applied by moves. Moods take the place of standard fantasy buffs or debuffs- for example, Excited characters have +25% speech and Enraged characters have 25% less defense.
In the middle of an adventure, you are allowed to build a campfire. The three characters relax around the campfire and you draw from a deck of cards. Each character has different campfire cards, and there are some basic generic cards that round out the deck.
As you can see from this screenshot, the presence of Yvonne has included a unique card of hers, which provides certain benefits- in this case, a bonus when you recruit a certain hireling. (Renown are "victory points" and accumulating renown is how you the high score and a good ending.)
Pedrinho (the bald black man) also has a unique card. Every character does- every character has something that only they can do, and only when resting. Some cards are not particularly interesting- Yvonne's just gives you a bonus for something you were probably doing anyways, and it's not often practical to try and recruit many Journalists. They're limited in number, for one. But still, it's a decent bonus.
One of my favorite cards is for a Russian fighter named Ivan- his card halves his attack but gives him a significant bonus to speech, turning him from a formidable brawler to a defensive speaker (sort of). Once used, this change lasts for the entire game, with no way to turn back. It's a powerful bonus, but you have to have been ready for it. You have to have built your party around it!
It's a series of very cool decisions by a very savvy group of game designers, and I love it. I wish I could see more of it.