bd_sample.xml

<scene name="init">
  <goto sceneName="intro" condition="!met_b" />
  <goto sceneName="root" />
</scene>

<scene name="intro" goto="root">
  <setGameVar name="met_b" value="true" />

  <line>Hello. Did you land in that balloon? Nice looking thing.</line>
  <line>Wish I had a balloon. Oh, I'd probably just ruin it. I suppose they know how to do things properly $[player_came_from].</line>
</scene>

<scene name="root">
  <line>
    Sorry I'm not more fun to talk to, $[player_name].
    <option goto="aboutThreeSpireSettlement">What is this place?</option>
    <option goto="whatAreYouDoing">What are you doing?</option>
    <option goto="joke" condition="got_joke_quest&!joke_quest_completed" hideIfNotAvailable="true">Do you know any good jokes?</option>
    <option goto="doYouHaveAnyCloth" condition="!accepted_delivery_mission" hideIfNotAvailable="true">Do you have any spare bits of cloth?</option>
    <option goto="completeDeliveryMission" condition="accepted_delivery_mission&gave_letter_to_worker&!completed_delivery_mission" hideIfNotAvailable="true">I found someone to carry your message.</option>
    <option goto="goodbye">Goodbye</option>
  </line>
</scene>