[A Role-Playing Game] is a game of communication. Where in other games you might move your pieces on a board, or play cards onto the table, in this game one player describes the board, and you describe your pieces, where they are, and how they move.
You use your imagination, but that’s not where it stays. You have to communicate what you imagine to the other players, so that they can include it in what they imagine. The result of all this imagining and communicating is a lively conversation, a fun free-for-all about what the imaginary characters in the game do, where they go, and what challenges they overcome.
Storming the Wizard’s Tower, Vincent D. Baker.