Harlowe

Harlowe is a story format for Twine 2, the web-based tool used to create interactive fiction. It is designed to be beginner-friendly and emphasizes readability and quick authoring. Harlowe provides a domain-specific language built around macros that control the flow of a story, handle variables, and render content. Writers create passages and navigate between them through links or macros that display dynamic text.

The Harlowe language uses parentheses to invoke actions, with syntax that typically includes assignments, conditionals, and display commands. For example, the common pattern (set: $score to 0) assigns a value to a story variable, while (if: $score > 5)[Text to show] displays content conditionally. Variables are prefixed with a dollar sign and are scoped to the current story. Other macros cover looping, lists, and content rendering, enabling authors to structure narratives without extensive programming knowledge.

Harlowe is one of several formats supported by Twine 2; others include SugarCube and Snowman. It is popular in educational settings and among beginners due to its approachable syntax and integrated editor workflow. Over time, Harlowe has evolved to offer improved variable handling, macro composition, and customization options for text and user interface elements, while maintaining a focus on clarity and accessibility.

Stories written in Harlowe are exported as HTML files for publishing on the web or sharing as standalone documents. Documentation and tutorials maintained by the Twine community provide guidance on macro usage, story design, and best practices for interactive storytelling.