Expressionist: An Authoring Tool for In-Game Text Generation

We present Expressionist, an authoring tool for in-game text generation that combines the raw generative power of context-free grammars (CFGs) with the expressive power of free-text markup. Specifically, authors use the tool to define CFGs whose nonterminal symbols may be annotated using arbitrary author-defined tagsets. Any content generated by the CFG comes packaged with explicit metadata in the form of the markup attributed to all the symbols that were expanded to produce the content. Expressionist has already been utilized in two released games and it is currently being used in two ongoing projects. In this paper, we describe the tool and discuss these usage examples in a series of case studies. Expressionist is planned for release in late 2016.