We all know the show went off the rails, but I've been thinking about which Game of Thrones fan theories might actually have been part of George RR Martin's original plan. The R+L=J theory was obviously correct, but what about some of the others?
Like the theory that the Three Eyed Raven is actually the Great Other, or that Bran will become the Night King in the books? I'm looking for theories that make sense based on the foreshadowing analysis in the books, not just wild speculation.
I'm convinced the Bran becomes the Night King" theory was part of GRRM's plan. The foreshadowing analysis is too strong - Bran's connection to the Three Eyed Raven, the Night King's creation involving a Weirwood tree, the fact that both can see through time.
In the books, there's so much emphasis on Bran's temptation to use his powers for control rather than observation. What if in trying to prevent the Long Night, he accidentally causes it? He goes back in time to stop the Children of the Forest from creating the Night King, but ends up becoming the vessel instead. It would be a perfect tragic ending for his arc.
The theory about the Three Eyed Raven being the Great Other makes a lot of sense when you do the foreshadowing analysis. Both are associated with cold, both seem to oppose the Lord of Light, and both have mysterious agendas.
What if Bloodraven isn't actually fighting the Great Other, but is the Great Other? He's been manipulating events for centuries, and his training" of Bran is actually about finding a new vessel. The symbolism in media like the weirwood throne looking like a heart tree could represent him being the "heart" of the Great Other's power. It's one of those Game of Thrones fan theories that would explain why the White Walkers seem to have their own mysterious purpose.
I think the Jaime kills Cersei to fulfill the Valonqar prophecy" theory was definitely planned. The foreshadowing is all there in the books - Jaime's golden hand could be the "hands" around her throat, his character arc is about breaking free from her influence.
The show messed this up by having them die together, but in the books, I think Jaime will strangle Cersei after she tries to burn King's Landing with wildfire. It completes both their arcs - Cersei's descent into madness mirroring the Mad King, and Jaime having to kill another monarch to save the city. It's one of those theories that make sense based on established character development.