Alright gather around everyone, its time for acting 101: Subtext!
What is subtext? For acting, subtext is the underlying meaning behind spoken words as interpreted by an actor. What does that mean? Basically you're adding additional meaning to your spoken words by the way you say them. I'll give you an example:
Lets say I have the following (cheesy) script for a scene I'm about to act in:
JOHN and MARY are alone in the bedroom. Mary is upset and John is comforting her.
"John: Mary, everything is going to be ok, I just want you to know that I love you."
Now if I'm going to play JOHN in this scene there is a lot of information I'm going to need in order to apply the proper subtext to my dialogue. Things like:
What is the relationship between John and Mary?
If they are siblings then the line would be spoken much differently than if they were lovers.
What happened just before?
What if this scene took place right after they had sex?
How would you reflect that in the above line of dialogue?
This is all information that can be implied with the proper subtext.
So.what does this have to do with game? EVERYTHING!!!