Sometimes a good joke has a great punchline but none of the characters are witty enough to say it, or a story can't move forward without a crucial skill or fact which none of the characters could possibly know. What's an author to do?
Toss one of them the Smart Ball!
Characters who catch the Smart Ball become knowledgeable regarding some trivia or discipline needed to deliver a punchline, discover clues, or implement a foolproof solution to whatever problem they face when normally such attempts fail. They may also become far better at effectively communicating information, allowing several characters to put their clues together to discover the villain's Evil Plan.
Using the Smart Ball is not necessarily bad. While it can be an Ass Pull if The Ditz suddenly demonstrates a keen skill at molecular biology, it's not much of a stretch to imagine the Jerk Jock also knows the results for every Super Bowl since 1966. If a character is tossed the Smart Ball enough times, they may even get Character Development that makes the smarts permanent. And sometimes the character saying the gag being normally an idiot can add on another layer of humor.
Mind, excessive use of this trope can be considered negatively if an author has to resort to this sort of thing too often, using it essentially as a Deus ex Machina to get the heroes out of a tight spot or to railroad a plot in a given direction. If it's a comedy though, no one minds thanks to the Rule of Funny.
Compare Informed Ability, when someone is said to have the Smart Ball in terms of a certain field, but it's rarely demonstrated, or Good with Numbers, when a character is suddenly endowed with math skills. Contrast Hidden Depths, which is what this often comes across as. See also Dumbass Has a Point, for when it is The Ditz instead of an ordinary person having the insight. When a character consistently picks the ball up when it comes to specific subjects, he's a Genius Ditz. If the ball is limited to crises or combat situations, he's a Crouching Moron, Hidden Badass. This trope is a relative of Sanity Ball, Snark Ball (which is about wit rather than intellect), and the opposite of Idiot Ball. Advantage Ball is a distant cousin. See also Bat Deduction.
Not to be confused with the video game of the same name.
