When Game of Thrones showrunners David Benioff and D.B. Weiss teamed up with with Alexander Woo for Netflix's 3 Body Problem, they didn't just bring their genre novel adaptation expertise. They also brought a few familiar faces.

Making the leap to 3 Body Problem are a number of Thrones actors, including Jonathan Pryce, Liam Cunningham, Conleth Hill, and — in a key role as one of the core friendship group that form "Oxford Five" — John Bradley.

The latter is both one of the best, and one of the worst, parts of 3 Body Problem. Here's why.

Remember nervous Game of Thrones bookworm Samwell Tarly? Well, John Bradley's 3 Body Problem character couldn't be much further removed. In the sci-fi series Bradley plays Oxford dropout Jack Rooney, a multi-millionaire owner of a snack empire who breezes through his scenes with the carefree dry sarcasm that only someone ridiculously young and rich could muster.

Rooney is a genius who has taken a different path to his fellow Oxford grads. Instead of science and academia, he's embraced money. Now he lives life in a bachelor pad that looks like what would happen if you gave a teenage boy an infinite allowance, gratuitously oversized drum kit, $13,000 Acer Predator Thronos Air gamer chair, and all.

The problem with a show about scientists struggling to save the world is it invites a certain level of seriousness. Bradley's character laughs in the face of this. Whether he's swearily reacting to the realism in the high-tech VR game sent by the aliens, being hilariously dismissive of the game's young Follower that needs constant saving, or casually roasting his friends, Jack Rooney is 3 Body Problem's Tyrion Lannister.

And when he and his friend Dr Jin Cheng (Jess Hong) start teaming up to play the game together, he really finds his stride.

"England again," says Rooney as they appear together in the VR world. "So you're in my game?"

"Mate, I've lived in England for 12 years," says Jin. "Maybe the game found something we're both familiar with."

"Oh, I don't like how it knows that. It better not have gone through my search history."

"Well if we see a girl farting on a birthday cake, we'll know," comes Jin's dry response.

This is just one of many amusing moments that breaks up a fairly dark show with some lightness. Jack is at the centre of almost all of these exchanges.

Imagine what Game of Thrones would have been like if Tyrion had died in Season 1. That was the feeling I had when Jack Rooney was unceremoniously murdered at the close of episode 3 of 3 Body Problem, just as his character was hitting his stride. His dry eye-rolling and double-act with Jin were so much fun to watch, and the absence of that is felt pretty badly in the next five episodes.

I'm not saying he should have been kept around to the end, necessarily, but episode 3 did feel a little bit premature. If we'd had Jack's sarcastic commentary at the beach house, or after the San-Ti launch their "you are bugs" attack, it could have added some laughing-in-the-face-of-the-apocalypse humour that, after Rooney makes his exit, is something the show's missing.

How to watch: 3 Body Problem is now streaming on Netflix.