Game of Thrones is a TV show that's kept high-concept big-budget fantasy alive on television ever since SYFY mutilated the genre.
Game of Thrones' storyline can be quite the clusterfuck to the uninformed viewer who doesn't start from the beginning. The best we can do to clear things up is divide them into three main story arcs:
War of the Five Kings
The Adventures of Daenerys Targaryen
Winter is Coming
The series takes place in the World of Ice and Fire, in which there are two continents: Westeros and Essos. Its a world thats been stuck in the Dark Ages ever since the Doom of Valyria, filled with hidden magic, kings, brave knights, LOTS AND LOTS AND LOTS OFF SEX, and ZOMG EPICBATTLZ!!!!! Butt not inuff weerd fairy tail creachers, sadly, so 1/10.
The show's cast is HHHHHHHUUUUUUUUGGGGGGEEEEE, so huge that we can't list any character here. Besides, so many characters on the show get killed off that even the writers of Lost find it baffling, so why bother? That's why this very wiki's got categories, goddammit!!
Game of Thrones is based on a series of books by George RR Martin, created by two writers casually called D&D.