also: さんだんオチ
noun
three-part joke; rule of three in comedy
A comedic structure where two similar, mundane setups are followed by a surprising third element as the punchline. Often used in Japanese manzai and comedic storytelling.
See also: 落ち (おち)
あの芸人は三段落ちを得意としている。
That comedian is good at three-part jokes.
The three-part joke structure is also often used in rakugo.