A long-time Rhy'din and RDI enthusiast by the name of Beth Codet once compiled an answer to the question of: What is free-form role-playing?  This is probably the best definition available, but the Nefarious SM has always been a fan of the more simplified definitions given by her dear friend Merriam Webster.

Webster's dictionary online defines role-playing quite simply as: to act out.  "Students were asked to role the thoughts and feelings of each character" in the transitive sense.  In the intransitive sense, role-playing is defined as "to play a role."  We here at Mutual Endeavors like to think of it more as remembering what it was like to be a kid again, playing in the backyard with your friends and pretending to be someone who you are not.  For role-playing in itself requires a great deal of imagination on the player's part.

Even the definition of "act out" emphasizes this thought by saying: 1 a : to represent in action <children act out what they read> b : to translate into action <unwilling to act out their beliefs>
2 : to express (as an impulse or a fantasy) directly in overt behavior without modification to comply with social norms

Essentially, role-players are textual actors.  They are the men and women behind the masks seen on stage.  Our stage just so happens to be online, in chatrooms and on message boards.  And the best part is that everything is ad lib.  There are no concrete scripts and nothing is predictable.  That's half the fun of role-playing.  Just so long as everybody remembers it's all make believe.

We don't want to grow up.  Why should we when we can still be Toys R Us kids?