You don't seem to understand what playing a role means.
It doesn't actually require the player to make decisions about what his character would do. Just like playing a film role doesn't necessarily mean you, as an actor, get to change the script or actions of the character you're portraying.
So, that's definitely both logically and semantically wrong.
On the contrary, this is exactly what playing a role is, whether you are performing in the theater, film, or playing a role in a role playing game.
You must consider your character's perspective (again "someone who bashes monsters" is not a character) and make choices, taking actions you think that character would take.
When you are performing as an actor in a film, obviously, you don't rewrite the script and go to a different location, etc. However, acting in a film is still all about your choices, just as playing a role in an RPG.
This is precisely how one plays a role, by considering the objectives of your character and making choices. On a 35mm close-up, the tiniest choices are magnified a thousand-fold. Even though you already know the outcome of the scene beforehand, you are going through this process, on camera, of choosing what your character would choose to do.
Certainly there are bad films and bad actors and cases where you could say someone is not even acting, just standing in front of a camera and reading lines.
But when an actor is truly acting, he is taking actions he feels his character would take, making choices he feels his character would choose, saying things he feels his character would say.
Your director might reject your interpretation of the character, perhaps he has a different opinion about what your character would choose to do in a given scene. As an actor it is your job to respond to the director's notes and find a way to justify that choice, perhaps by coming up with some reason in the backstory as to why the character would take that particular action your director wants you to take.