What is 雙部曲?
雙部曲（或稱二部曲）是一種兩部分的敘事格式，透過兩個緊密相連的篇章提供一個連貫的故事敘述，常聚焦於兩位主角或兩個互扣的視角。這是浪漫小說中用於從互補角度探討關係的熱門結構。
在出版領域，雙部曲指以一個緊密相連的故事弧為單位、以成對的兩本書發行的形式。雙部曲可以呈現多種形式：將一個連貫的情節分成兩冊、兩本互為姊妹篇但從不同角度描繪同一段關係、或兩本書涵蓋戀情的序列階段（例如邂逅與後果）。與較長的系列相比，雙部曲能讓作者比單獨出版的作品更深入地發展角色與衝突，同時讓讀者的投入負荷更易於承受。
Usage example
作者推出一部雙部曲，其第一本以女主角在夏日愛情中的觀點為主，第二本則從男主角的角度重新敘述同樣的事件，揭露第一本書僅暗示的秘密。
Practical application
對於創作者與如 Endless Romance 這類平台而言，雙部曲在節奏掌控、互動度與行銷方面相當實用：它們讓作家在兩冊中分散情感高點、透過中段裂點增強悬念，並鼓勵讀者回到第二冊。對讀者而言，雙部曲提供更豐富的角色探討，而不需經歷多部曲長時間的閱讀負擔，亦便於進行可分享的「觀點比較」討論，提升社群互動性。
FAQ
Is a duet the same as a duology?
Do I have to read both books to get the full story?
It depends. Some duets are written to be read together for the full experience (with cliffhangers or complementary revelations), while others are structured so each book can stand alone but gains depth when read as a pair.
How does a duet differ from a longer series?
A duet focuses on one complete arc spread across two books, keeping storytelling tight and focused. Longer series expand the world and characters across three or more books, which is better for sprawling plots or many secondary character threads.
How can duets be used in interactive romance apps?
In apps like Endless Romance, duets can be implemented as two linked interactive arcs (for example, alternating perspectives or sequential chapters). This encourages replayability—players can play both sides, compare outcomes, and return for different choices—while allowing staggered releases to sustain engagement.