As you’ve probably heard by now, HBO has decided to renew Game of Thrones for a second season, even though the first episode only delivered so-so ratings — an estimated 4.2 million gross viewers tuned in on premiere night. Given that the show is going to be around for a while, we thought that this cheat sheet charting the relationships between the different houses might be helpful for those of us who haven’t tackled George R. R. Martin’s epic books yet. Click here to view the larger version. [via Pop Culture Brain]