As interactive narratives, by definition, change according to the user's choices (dynamic story), so do the dialogue utterances by the characters. Writing all possible utterances manually faces scaling problems. This motivates the use of natural language generation techniques. We present ExpReal, a surface realizer and templating language that allows authors of interactive narratives to write flexible and enriched templates while maintaining control over their use. Templates are automatically selected based on author-specified conditions relating to the world state (e.g. characters' emotions) or the current task at hand. ExpReal has been developed to support at least three languages (English, French and Dutch).