I have a degree in acting from a fine arts college and have done work on stage and in film and television (low-budget fringey stuff you won’t have heard of). I also write, direct, and coach.
I like to say that acting is so simple, it’s difficult.
Forget everything you think you know about acting. Is it pretending? Sort of, but not exactly. Is it emoting? Sort of, but not really. Is it about becoming someone else? Sort of, but not exactly. And so on.
Really, what acting truly is is a difficult thing to answer. At root, though, I believe that it is simply being and doing.
I’m going to suggest first that you get a hold of True and False by David Mamet. He espouses an extremely stripped-down vision of what the actor’s craft should be: learn the lines, pursue the objective, and do nothing else ("…nor do not saw the air too much with your hand…"). His philosophy is probably too minimalistic for my taste; while I certainly agree that there’s a lot of fat and folderol to be trimmed from the typical performance, what he says in the book goes beyond fat and into cutting bone. Still, it’s an excellent reference point for rethinking what should be important for the actor.
What others have mentioned here as “motivation” is more commonly called “the objective.” What is it the character wants in the play, and in the scene, moment by moment? For example, Hamlet (since I quoted him above) wants to be revenged on his father’s murderer. He can’t just do that immediately, though, because said murderer is now the king. So he must pursue a lot of mini-objectives while he builds up to his central goal. He attempts to convince Polonius he’s lost his wits. He recruits the players to re-enact the murder as it was explained by the ghost. He gets his mother on his side. He figures out what Rosencrantz and Guildenstern want, and counters it. And so on.
Without an objective, without a driving need, the character has no life, and might as well be a potted plant.
But that’s not all. You also need tactics. In other words, what does the character do in order to achieve the objective? And it’s here that the character really comes alive for an audience, because how the character goes about achieving his or her ends, and what he or she is willing to do, how far he or she will go, tells the audience everything it needs to know about the character. Tactics (sometimes called actions) are the window into the character’s nature.
Say I’m playing a character who wants another character to give him a hundred dollars. That’s my objective: get a hundred dollars from the other person. Now, how do I go about this? The scriptwriter will provide the tactics in the broad strokes; do I threaten, do I talk, do I assault, and so on. But there are fine shadings of interpretation, choices by the actor, that give the character its life and specificity. If, according to the script, I only talk, how do I talk? Do I wheedle and beg? Do I intimidate? Do I charm and befriend? Where am I in relation to the other person? Do I stand far from and face away? Do I stand close? Am I sitting at their feet or looming over them? Different characters will use different tactics, and it’s those tactics that illuminate the characterization for the audience.
There are variations on this approach. One lecturer who visited the school talked about an emotional objective in addition to the physical objective: I don’t just want my adversary to give me a hundred dollars, I want him to feel happy about it, or whatever. I don’t really buy into that, because I think the physical objective is paramount, and the emotional objective is just a step on that road— I will use a tactic to elicit an emotion in the adversary as a means toward achieving the ultimate goal. That’s more of a philosophical difference, though, and may appeal more to other actors.
Now, the thing is, you should notice that all of this is directed at the other character. I’m not thinking about what I’m doing simply for the sake of my doing it. It’s all in pursuit of something that is to be acquired from the other person, whether it is an object (a hundred dollars) or an action (a kiss) or information (the name of a lover) or whatever. If I am invested in my objective, and if I understand my character enough to know which tactics are valid and which are not valid (i.e. which are “out of character”), then the scene, really, will take care of itself.
And the interesting thing is, this mirrors quite effectively the way things work in real life. Consider: I’m sitting here at work. I don’t have anything immediately pressing, so I can entertain myself here on the Dope. Now, my phone rings. Someone is invading my psychological space, no doubt because they want something from me. I immediately need to find out what they want; that’s my first objective. Let’s say I find out they just called to chat— but I don’t really want to right now. My objective then becomes to get them off the phone so I can hang up. I have various tactics I can use for this: Perhaps I am brusque in my demeanor so they get the sense that the conversation is unwelcome, or perhaps I lie to them and say I’m working on something else and don’t have time to talk. Or, perhaps, they succeed in their objective and convince me that a conversation is worthwhile, maybe by mentioning they have information in which I am genuinely interested. Either way, the format by which actors analyze and build a scene, objective and tactics (and obstacles, i.e. what they need to overcome), captures remarkably closely the dance of human interaction in real life. It just organizes and labels it in a way that helps the actor figure out how to perform the scene and the character.
And that’s why I said what I did: Acting is so simple, it’s difficult. It’s simple, because we all do it every moment of every day. We all want things, we all pursue those wants, and we use different means of achieving them. Some of us are more effective at certain things than others. Some of us repeat the same tactics over and over; some are skilled at trying different tactics, different means to the end. Where it gets difficult, however, is that we’re not used to pursuing our objectives with unfamiliar tactics. Actors learn to step beyond their personal characters and take on the mantle of other people, by which, in the simplest and most straightforward sense, they drop their own toolbox of tactics and pick up another one. If they themselves are more likely to defuse a tense situation with humor, they may choose to play a character such that he handles the same situation with bluster and escalation. If the actor in real life flirts with a prospective mate with adolescent teasing, she may choose give a character a different approach to courtship, flirting by compliments and empathy. That’s why it’s simple, and yet difficult: All you have to do is be a person, but to really be an actor, you have to be a person other than yourself.
(Which isn’t to say some actors don’t do well just playing themselves over and over. Movie stars, for the most part, are just immensely charming people with a limited set of tactics that come across as enjoyable and likeable in performance and which they can use over and over. Nothing wrong with that, though whether or not it’s “acting” is probably a debate for another thread.)
So: How does this apply to what you’re talking about in your roleplaying game? How can you use this? Because it seems to me that what you described was acting as a character, conveying mannerisms and accent and behavior, more like an impersonation than a performance. That gets into the craft of acting, learning how to do dialects and studying physical movement so that one’s body and voice become instruments to be played as desired. That, I think, comes with training and confidence, and is more of a technical skill than an art. It has about as much to do with the creative process of acting, I think, as does learning the circle of sharps and flats that define the keys in sheet music. It’s a necessary piece of knowledge, but the more you do it the more you aren’t even conscious of it, and the more you can do it automatically in order to proceed to the more interesting challenge of interpreting the actual music. Same goes for acting: We study voice and dance and textual analysis and kendo and everything else in order to build up our repertoire of possible choices for the character to make in the scene.
Still, by taking the approach to the characters you’re impersonating of looking at the world from their point of view, thinking about what exactly it is they want to achieve, what they want to get from your players, and how they’re willing to go about obtaining their objective(s), you can take yourself out of your own self-consciousness and stop thinking about your own performance. It always comes out of the other person. As the character, decide what you want, and how far you can go to get it, and then go after it. You’ll find yourself acting without even really thinking about it.
I hope this is helpful. I could write another ten thousand words on the subject, but I hope this is a useful introduction to at least the general principles behind what an actor— at least, a good actor— is doing when he approaches a performance. And do take a look at the Mamet book; like I said, it goes too far, I think, in its method, but it’s quite useful for blowing away a lot of the extraneous gibberish that tends to surround something so ephemeral, so paradoxically intuitive yet counterintuitive, as the craft of acting.