Lets start with LARP. This stands for “Live Action Role-Playing”.

Descriptive but not very informative to the everyday person/player?

Lets try this:
Role-Playing is taking upon the character or persona of a fictional character for the duration of a game session. Mingling your creativity and personality with rules based abilities to create a whole new fictional person.

When you play/become this person for a evening you get to free yourself in a playful, exhilarating way while remaining safe. Free your imagination, experience a little of the “Romantic” side of being a Vampire or the horror of playing the slippery slope of allowing their predatory nature slowly gain more control.