We create a story world where we are not just the actors but also the script writers. It’s a co-operation between us, and each of us has in our imagination a character that we play, a role. We do our best to behave in the same way that our character would, be they rich or poor, aggressive or meek, honourable or cheating.
Of course even fantasy characters have limits and as we create our stories others create theirs as well, so to be fair we take turns, waiting to see how others react and adapting as the story takes unexpected twists. If I push someone do they fall or push back, are they angry surprised or afraid. That’s their role and decision. If role play works well its a great creative experience and a lot of fun!
Be careful not to ‘meta game’, use knowledge that your character would not have or ‘god mode’, force your decisions on others. Also try to be consistent and think in the way that your character would.
Often we use meters to decide outcomes in combat or keep track of trades for example, but more about that another time.