This episode continues the show's tradition of killing off a different king each season: Season 1 - Robert; Season 2 - Renly; Season 3 - Robb; Season 4 - Joffrey; Season 5 - Mance Rayder.
Although the novels have a significant amount of flashbacks, showrunners David Benioff and D.B. Weiss had set rules of 'no dreams, no prophecies, no flashbacks' for themselves when they began with the series. They especially wanted to eschew flashbacks, as their original unaired pilot had several, which became very confusing. All these rules would eventually be broken, as this episode contains the first flashback in the show's history.
The first time that Daenerys' dragons Viserion and Rhaegal are mentioned by name on screen. Drogon's name was first mentioned in The Children (2014).
The episode title refers to Mance Rayder's words to Stannis "I wish you good fortune in the wars to come" and Varys' words to Tyrion "I believe men of talent have a part to play in the war to come."
The first episode to show Winterfell with Flayed Man sigils in the opening credits sequence, signifying the Boltons having taken over the castle in the previous season. It is also the first time since season 1 that Pentos and the Eyrie appear in the sequence again. Although the Eyrie is not visited in the episode itself, it stands in for Lord Royce's Runestone, which is also in the Vale.