As Kotaku reports, EA/BioWare senior product manager David Silverman seems to think that there are four different methods to play Dragon Age: Origins. I don't really understand why such a breakdown is necessary, but here it is anyway:
The most basic way to play the game is as if it's an action-RPG, Silverman said. Control one sword-swinging hero. Let the computer control the rest of the characters. So if my play style is a mixture of #2, #3, and #4, is that a fifth method?
A slightly more involved way to play would be to treat it like a massively-multiplayer online game for which you have multiple characters. As you adventure with your party, a player can switch control of characters on the fly. On the PS3, this is done with a tap of a shoulder button, swinging the camera from one member of your party to another, as the whole group of them keeps walking around or, more likely, battling.
The third way to play, according to Silverman, is the Kingdom Hearts style. This would involve the player sticking with a lead character, but swapping ally characters in and out to take advantage of their various specialties. In addition, players could, assign general combat tendencies to their allies, asking them to go all out, hang back that sort of thing.
The fourth and deepest way to play is to emulate the most hardcore way of controlling Final Fantasy XII. The Square-Enix RPG had a "Gambit System" that allowed players to collect and apply preferences to the artificial intelligence routines of partner characters. An example of a collectible gambit would be a script that would tell an ally to cast a healing potion on herself any time her health points drop below 30% of the total.