Story is the backbone of SWTOR, so much so that it is the primary thing that differentiates it from competitors.
BioWare developers have been harking on for years about how much story is the 'fourth pillar' that they are adding to the traditional three pillars of progression, exploration and combat, but until you actually experience it for yourself it is difficult to see how much they have really put into this part of the game.
The writers at BioWare are considered developers in their own right and they have been working on the game for longer than anyone else – in fact, up to two years before the systems and graphics designers got involved.
While BioWare has an expansive universe of canonical Star Wars lore to work with, it does not rest on its laurels here, but freely adds to and expands upon what has gone before. The game is set 3,500 years before the movies in a time of uneasy peace between the Republic and the Empire, and a period where hundreds of Jedi and Sith existed. This gives BioWare room to come up with its own tales, much like those it wrote for the Knights of the Old Republic games, which this is, in essence, a sequel to.
Part of what makes the storytelling of SWTOR so engaging is the fact that you have a choice in how the story plays out. Dialogue choices affect whether someone lives or dies, gets freed from prison or sent off to be tortured, and you can play things as a goody two-shoes, the most evil person in the universe, or somewhere inbetween. Not only will you get Dark Side or Light Side points depending on your choices, but characters will send you mails telling you what happened and giving you rewards, or refusing to reward you, depending on your actions.
Another part of the immersion factor is the fact that all dialogue is completely voice-acted, an immense undertaking that makes the rumoured $130 million game budget sound pretty appropriate. Some character lines are reused in responses to NPCs, but this is relatively minimal.
The story elements make the game somewhat cinematic in style, adding a lot of time where you will be simply engrossed in the unfurling plot. However, some players who just want to explore or kill things might not like this effective downtime and can skip through dialogue instead. We highly recommend that this approach be avoided, however, as that only serves to remove the heart of the game and what makes it so enjoyable.