In this installment, I'd like to talk about one of the keys to player retention: the extended storyline, or story arc. Now, you may have an excellent original theme or perhaps you've built a game based on a popular established theme, and thus you think that all you must do now is open the doors, throw up a website, and watch the hordes come in. Sorry, no. And once you've crossed that bridge, or built that house, you need to keep pointing toward the horizon, toward what comes next. Keep them guessing. Keep them interested. Now let's backtrack a little and talk about designing a single storyline.