Why did Game of Thrones only have 7 episodes in season 7? Usually they have 10 episodes per season.
Game of Thrones don't have novels to follow anymore. It was stated many time that Martin already shared the ending with HBO team but they don't have each and every single detail which Martin will add in his novel sooner or later. They have to make their own story and also to shoot more expensive fights.
So the reason seems to be lack or story detailing in the absence of novels and increasing cost.
From metro.co.uk, this is what one of the cast member said about it:
‘They are taking the length of time it takes to shoot ten episodes to shoot just seven this year and six next year,’ Iain Glen, who plays Ser Jorah in the show told RadioTimes.com.
‘I think the scale and size of the set pieces, the world that is being created it’s just getting more and more extraordinary,’ he added. ‘They feel they need that time to shoot seven hours as opposed to ten.’
Season 7 of Game of Thrones had only seven episodes due to less story content remaining, increased production values and the time required to film the episodes involved larger set pieces than in previous seasons.
Caveat. How do I know this it? I googled Season 7 Game of Thrones. So this answer may not be complete.
Following their explosive season six finale, Game of Thrones co-creators David Benioff and D.B. Weiss have made it clear that there are only but a handful of episodes left to spread across the final two seasons of their HBO hit. "It's two more seasons we're talking about. From pretty close to the beginning, we talked about doing this in 70-75 hours, and that's what we'll end up with," Benioff told Deadline. "Call it 73 for now."
For those not keeping score at home, each of GoT's six seasons have been made up of 10 episodes each, bringing the series to a current total of 60 hours and leaving us with only 13-15 to hit their target.
They’ve decided on the 13 episodes between the final two seasons based on how far they think they can take the story.
Honestly, this wasn't hard to find.