dialogue-systems

dialogue-systems is an engine-neutral game-development skill for building branching dialogue and narrative — modeling conversations as a graph where nodes hold lines, choices branch the flow, conditions gate options, and variables remember what the player did. It frames the first real decision as build-vs-buy: adopt a proven authoring tool (Ink or Yarn Spinner) or write a small data-driven runner. The skill owns both Ink and Yarn and is consumed by genre skills like visual-novel and rpg.

Its core workflow guides choosing the authoring approach, defining a node contract (a node yields a line, a set of choices, a command/side-effect, or an end/jump), separating variables from flow via a variable store gated by conditions, localizing from the start with line IDs rather than raw strings, driving the graph from the game loop as a state machine, and verifying by walking every branch. It provides concrete patterns: an engine-neutral JSON dialogue graph, a runner step machine (shown in GDScript), and Ink/Yarn examples. Two references round it out — a side-by-side Ink vs. Yarn Spinner syntax cheat sheet and a complete custom-runner design that notably includes a tiny, sandboxed AST-based expression evaluator with an explicit warning to never eval untrusted strings in a way that exposes the host language.

The target users are game developers and narrative designers building conversation trees, choice menus, or narrative state (flags, relationship values) that affect later dialogue, across engines like Godot and Unity. The skill deliberately defers engine UI, cross-session persistence (save-systems), and resource formats (godot-resources, unity-scriptableobjects) to sibling skills, keeping its focus on the dialogue graph and its interpreter.