The Assassin’s Creed movie might not be coming out until December, but director Justin Kurzel is already building up the hype. After a Total Film interview in which he revealed that he was already looking at the possibility of a sequel, today he discussed how the movie was made, how the characters fit into their 15th century Spain setting, and how many bones were broken.

In a Facebook Live interview with GamesRadar, Kurzel answered a bunch of questions about his new film. Though there were standby stuntmen on hand to handle the tougher stunts, like the 125-foot “leap of faith,” many actors did many of their own, including Michael Fassbender.

He did a lot of the stunts himself. He did a lot of fight sequences himself. That was really important to both of us. That it actually looked like our Assassin was actually him all the time and who you saw was the actor playing him. We were much more involved in the physical action than we were previously in Macbeth.

Because of the crazy amount of practical stunts, there were plenty of injuries.

We wanted the Assassins to be climbing up buildings, fighting in 40 degree heat on top of churches and doing a real leap of faith. We definitely wanted to go a little old school with it and make sure our Assassins didn’t sort of float and dance in the sky and that they actually felt very human and you could feel the punches, the falls and the crashes. There’s many jumps that are quite extraordinary. We had people breaking their ankles and legs. There was a lot of  carnage that went with the stunt guys and also Michael and Ariane in terms of the bumps that they encountered.

And what about those odd tattoos?

I think because we were in Seville and there was a very strong Middle Eastern reference throughout, a lot of the art and a lot of the costumes were very inspired. With the Assassins in our film it felt like they were travelers. Like they had picked up some things here and there and there was something very tribal about them. We got quite inspired by certain sort of tattoos that could define them and they could still be hidden under the hood so the stealth would still work. We were really interested in the Creed and what the Creed meant at that time and I guess that kind of Middle Eastern influence that started to sort of creep into the Assassins’ look and feel for the film.

It sounds like the crew really did their homework on how to integrate the video games’ plot with real history. Assassin’s Creed also stars Marion Cotillard, Michael K. Williams, Jeremy Irons and Brendan Gleeson, and will slip stealthily into theaters December 21.