trilogy

This term describes a cohesive narrative or artistic arc split into exactly three installments. It carries a connotation of completeness and structural balance, suggesting that the story requires three distinct phases—typically a beginning, a middle, and a resolution—to be fully realized. While a series can be of any length, a trilogy implies a deliberate design choice by the creator to limit the scope to three parts.

In professional and academic contexts, the word is used across various media, from classical Greek drama to modern cinematic franchises. It is distinct from a triptych, which refers to a visual artwork divided into three panels rather than a sequential narrative.