The first rule is "the rules can change at any time" as Shaun and the sheep take on the pigs in a comically chaotic game of ball—and then some.

It's a hot day, and Shaun is in the meadow, tossing a tennis ball up and down, looking for mischief. Boink! An annoyed Bitzer swings at the ball with his dog bone, sending it sailing across the meadow. Soon the flock has joined in a frenetic game of Bitzerball, with flowerpot bases, sprinkler hazards, and a hopelessly complicated, wildly shifting set of rules. And that's before—squeee!—the pigs get involved. . . .