NeREEna

NeREEna is a next‑generation narrative engine developed by the Institute for Interactive Storytelling (IIS). Conceived in 2019, the project aims to merge machine learning techniques with adaptive plot design, enabling stories to evolve in real time based on audience reactions. The core technology, dubbed the Reversible Narrative Engine (RNE), employs reinforcement learning to reweight plot arcs and character motivations as input data streams from biometric sensors and user choices.

The engine was first publicly unveiled during the Digital Arts Conference in Berlin in 2021. Its prototype was tested through a live interactive drama titled “Echoes of Tomorrow,” in which 312 participants controlled characters in a dystopian setting. Early reviews praised NeREEna’s capacity to preserve thematic coherence while allowing significant narrative divergence. However, critics noted that the system’s computational demands limited widespread deployment on consumer devices.

By 2024, NeREEna had been licensed by several major game studios and educational publishers. The IIS released an open-source SDK that permits developers to integrate the engine into text‑based and graphical applications. While the technology is still evolving, it has sparked academic interest in the field of interactive narrative design, with several publications exploring its implications for authorship and reader agency.