I think the concept of "getting into character "as used by most actors and directors is a myth perpetuated by followers of Stanislavsky who do not understand what he meant by being in character. Being in character simply means that the actor at all times while on stage is energetically focused on what is happening in the play and energetically responding to it. . He is concentrating on the play and not thinking about other things. It is actually possible to tell if the actor is doing this by observing him. When the actor lets his concentration wander or stops energetically focusing on what is happening in the play, you can see his posture relax and his gaze shift. It is as though the character the actor is playing suddenly is pulled though the floor revealing the actor standing there. This is called “dropping out of character.”
Stanislavsky was one of the most influential advocatea of the principle that all actors on stage must stay in character all the time. His writings on how he retrained the Russian actors of the early part of the Twentieth Century to change from their former acting style of artificial posing and only being in character when they spoke to presenting more realistic performances created world-wide enthusiasm for realism in acting. One of his books is entitled “Creating the Role” and those who read the book often confuse the difference between applying Stanislavsky’s systematic approach for the actor to represent the character with the idea of the actor actually creating the character. It is the playwright who creates the character when he creates the play. The playwright reveals the character though the stage directions and dialog. What the actor does is represent the playwright’s creation, the character, by using those stage directions and the dialog. How the actor goes about preparing himself physically, mentally and emotionally to do that representation is the stuff of the Stanislavsky System or Strasberg’s Method, or any other technique or approach to playing a role. But it is not creation; it is representation.. It is merely the actor standing in for what the playwright has created. That is why acting is commonly referred to as a craft rather than as an art. Of course what the actor does may be quite inventive and original, but if it is to be valid, it must represent the author’s creation in an accurate way.
The speeches of the script are the outward expression of the emotional and physical responses of the character that has been created by the playwright or screenwriter. They contain both the action the character is doing and the emotion he is feeling. The actor does not create these things that make up the character. He represents the character.
The first thing the actor does is to provide the outward appearance of the character. He is usually cast as a character whose outward appearance is much like his own. To this he adds posture, gesture, mannerisms, and voice. He is aided by costume and make up. All of which aid the representation of the character. The actor does not 'get into character;’ he concentrates on what is happening in the scene and reacts to it. That is what people really mean by ‘being in character.”