If you’ve ever heard a lifeless performance, you could tell something was definitely missing — it might have seemed as though the actor wasn't really into the role, or didn’t care, or just wasn’t very good. It’s easy to recognize, but a lot harder to explain exactly what is missing. If you were on stage yourself, your director might say, “give me more,” without explaining more of what — the missing element is energy. One site describes it like this:
In acting terms, energy is difficult to precisely define. Other words that are similar, but not the same, are impulses, moods, qualities, emotions, states-of-being, archetypes, points of view and vibrations. Energy encompasses all of these.One way to think of it is as a kind of intensity; the difference between an actor reading lines from a script and a character saying them. For example, listen to this next line:
To create energy. you must develop an idea of the mindset of the character you are voicing. Note that there can be more than one valid interpretation; you need to pick one. In later lessons, we will talk about how to decide which interpretation to use. In a very real sense, energy is the “spirit” of the character. What is said is not driven only by what the character is experiencing or doing, but also by who he or she is as a person.
Now we see that when performance “lacks energy”, most times this can be fixed by a stronger commitment to the character you are portraying as a whole, or performing with more awareness.
Think of a person’s entrance into a room, how you or a group reacts. The energy in the room is changed, but it can’t be properly explained. Some might call it charisma, others might describe it as a characteristic of a role or position they hold. A doctor may seem understanding, a teacher nurturing, a sales rep encouraging, all by nature of the role they play.
In performance, we can see the difference in energy between rehearsals and performances. During a show before an audience, the performers feel a hightened awareness, attentiveness to their show and commitment to the show or art on display. The same goes for public speaking — anything in which one puts oneself on display for an audience.