Rules are meant to be broken. This isn't even a rule. But it's good to know. A lot of comedy follows this structure, and if you pay attention, you'll notice some of your favorite bits from shows you love are doing this exact thing.
PREMISE
The basis of the scene/sketch. Here you'll be introduced to characters, setting, world, tone, etc.
ESCALATION
Something weird is highlighted.
ESCALATION
The weird thing gets weirder.
ESCALATION
the weirder thing gets weirdest.
TWIST
Pull the rug out from under the audience. Subvert expectation.
Comedy operates in threes. Or fours. Or fives. Or sixes. There're no rules. But a lot of the time it's threes. So try to hit your escalation three times. Unless four is funnier. Or five.
Here's the funniest scene to have ever been written. It's original.
PREMISE
A tasty treat falls off the kitchen counter onto the floor between two hungry dogs. The owner doesn't notice and walks into the other room. The dogs look at each other, then back to the treat.
ESCALATION
DOG 1 calmly states that DOG 2 usually gets more food, therefore DOG 1 should get to eat it.
ESCALATION
DOG 2 takes out a leather-bound ledger and leafs through to locate and reference data proving that food distribution has been balanced down to the individual kibble.
ESCALATION
In the bathroom, the CAT (new character, sorry) slams down a gavel from atop the sink, ruling in favor of DOG 1. The CAT cites a solid argument and a well presented case. DOG 2 accepts the verdict and the two dogs calmly return to the kitchen.
TWIST
The owner is picking up the food upon their return and says something like "Glad I caught this before you two did!" The dogs violently maul the owner, who bleeds to death as they feast on his corpse.
*(If you forget, think P.E.E.E.T!)
