Three... Two... One...

A Genre Savvy character knows what's going to happen next when the Genre Blind character does something stupid. So they voice that outcome and count down.

"Three... two... one..."

The outcome happens exactly when the countdown ends.

Related to Exact Time to Failure. Not to be confused with the gameshow ~321~ or the Class 321 Electric Multiple Units.

Film - Animated

 * On the first Ice Age movie, Manny and Diego do this in unison as Sid sits in a geyser, with Manny mentioning how faithful it is.
 * Kovu does this in sequel to The Lion King. In this case, he was counting down the time until Kiara attempted to pounce on him.

Film - Live-Action

 * The Joker in The Dark Knight waiting for the bombs to go off at the end.
 * The Goonies - the framed map is passed to Chunk specifically because the others know he'll smash it open by accident. They even count down in unison to the crash.

Live Action TV
"[Al has gone outside to fix the roof] Peggy: You know how you are always complaining that your father never does anything with the family? Well, just watch that window and your father has a big surprise for us. Right about now - three, two, one... [Al screams and falls past the window, family laughs and claps]"
 * Babylon5
 * Married... with Children:

"[Isaac has told Dana about a new bid from Quo Vadimus] Dana Whitaker: Isaac doesn't trust that when he tells me something, I can be cool. He thinks it's gonna spread around and the information'll get all twisted and I'm going to show him he's wrong. Isaac Jaffe: [While in his office] Three, two, one... Jeremy Goodwin: Isaac, I don't know if you heard. Six this morning there was a bid from an Italian airline called Platypus."
 * Sports Night episode "Quo Vadimus"

"Carla: He's slowing down, but he's still got it. Sam: Gimme a break, Carla. There's lead pipes down there. Interferes with the radar."
 * Out of This World did it when the uncle had some Love Potion in the form of cologne on, and when he was about to take a swim, the daughter and mother counted down for when the Instant Harem would abandon him.
 * Double subverted in a Cheers episode. A beautiful woman walks into the bar while Sam is in his office, and Carla does the countdown. It's as if the show is admitting how predictable it is, but Sam is two seconds late. He comes out, asking, "Where is she"?


 * By Community's second Christmas episode, the glee club have become so predictable that Annie can count down to their 'hip-hop remix' of carols.

Webcomics

 * Home On The Strange, with the drinking game.

Web Original

 * Often used in LOLcats captions, as seen here.

Western Animation

 * Bubbles in Powerpuff Girls, during an episode in which the girls try to defeat a particularly tough monster in their own ways.
 * In Superman: The Animated Series, Gsptlsnz counts down how many seconds it takes Superman to defeat Mxyzptlk.
 * Phineas and Ferb