Game Of Thrones: Is Gendry Really Cersei Lannister's Son?

The Verdict

Without the show outright confirming it, there isn't any ways of saying one way or another whether or not Gendry really is Cersei's son, and hey, that's why it is a theory. But we can weigh up the evidence for and against and look at which side is stronger.

In the case for, we largely have some circumstantial evidence. Mentions of hair colour, and the ostensible importance of Gendry, to push the notion that R+C=G. In the case against, the evidence does feel a little more tangible: it's a bit more rooted in the books, in what we've seen on screen, and what we know of the characters. There are still caveats to the evidence against, but you have to stretch just a little bit more to try and make it work.

R+L=J was such a great theory because there was so much evidence, and absolutely everything added up. But because of that, there's a tendency to look for his major parentage reveals. Gendry won't be Cersei's son in the books. There is a chance he could be in the show, but if he is, they've not done a huge amount to set it up, and are running out of time to reveal it, so as of right now, there's an even greater chance that he ISN'T Cersei's child.