There are three things you have to know in order to be a good Assassin: how to tell who your enemies are, how to throw a dagger, and how to jump off of things. In this new clip from Assassin’s Creed, Michael Fassbender’s Callum Lynch/Aguilar knows his enemy (it’s easy to tell when they’re aiming a crossbow at you), throws a ton of daggers with deadly accuracy, and takes one death-defying leap of faith.

The stunts in this are the real stars, and most of them are practical. Some of the stars even revealed that bones were broken on set by actors and stuntmen alike during production, due to the director’s objective to keep the CGI effects as minimal as possible. The Assassin’s Creed games are known for their ridiculous amount of acrobatics, but because it’s a video game of course it doesn’t look very realistic. Whatever your preliminary feelings about the movie are, it’s kind of reassuring to know that we won’t see a person do something they couldn’t do in real life.

The clip actually raises a lot more questions than answers, particularly about the Animus. When it cuts back and forth between Callum in Aguilar’s body and Callum in the warehouse, are we seeing what he’s seeing? Is it a hologram? How can Marion Cotillard tell when he’s about to jump? The CGI in this case is a little confusing, but hopefully it’ll make sense in the actual movie.

Assassin’s Creed opens in theaters December 21.