Dickon Tarly was recast due to a scheduling conflict experienced by the original actor, Freddie Stroma.
The Reason Behind the Recast
When Game of Thrones season 7 was set to begin production, Freddie Stroma, who initially portrayed Dickon Tarly in a brief appearance in season 6, was unavailable. He was committed to filming the sci-fi television series Time After Time, which prevented him from returning to the role.
The New Actor and Expanded Role
Following Stroma's departure, the role of Dickon Tarly was taken over by Tom Hopper, known for his work in The Umbrella Academy. The seventh season of Game of Thrones provided the character with significantly more screen time and storyline involvement, making his presence more prominent than in previous seasons.
