In typical Final Fantasy fashion, the story oscillates between complete clarity and total convolution at various points, but aside from some potentially confusing terminology to sort out – l'Cie, fal'Cie, Cie'th, Sanctum, PSICOM – FFXIII's story is surprisingly straightforward.
Without spoiling too much, the basic gist is this: The small, floating society of Cocoon lives in fear of Pulse, the mysterious planet below. This fear is perpetuated by the all-powerful government, which is actually controlled by ultra-powerful higher beings called the fal'Cie. Fal'Cie exist on both Cocoon and Pulse, and they exert their power by branding humans as l'Cie, servants to carry out their bidding. L'Cie are bound to carry out the mission given to them by the fal'Cie (called a focus), and if they don't complete it within a certain amount of time they'll turn into undead monsters called Cie'th. If they do complete it, their fate isn't much better – they're turned into lifeless crystals indefinitely. Lightning and company have all been turned to l'Cie, and unclear on which side they should be fighting for, they struggle with the dilemma of whether to complete their focuses or attempt to fight against their fate.
Above: Sazh is easily the most likable character, and his story is the most heart-tugging. Vanille grew on us too
Since FFXIII has eschewed a more traditional format in favor of a more controlled experience for the sake of the narrative and pacing, we have to point out that the opportunity to tell a truly compelling story feels like it's been squandered in some respects. To be sure, Lightning's story isn't uninteresting by any stretch, but it certainly isn't above and beyond what we'd typically expect.
In a way, a JRPG plot with no melodramatic scenes, no navel gazing exposition, and no overly sappy romances is a refreshing concept. Lightning's team is on a mission, and they don't stop much to share and learn and grow with each other. Because of that though, some of the characters come off as one-dimensional and boring, especially Lightning herself.