rules:
  # sleeping logic
  - match:
      type: actor
      sleep: rested
    chance: 0.1
    set:
      sleep: tired

  # sleeping initialization
  - rule: |
      "sleep" not in attributes
    set:
      sleep: tired

labels:
  sleep:
    rested:
      backstory: You are well-rested.
      description: They look well-rested.
    tired:
      backstory: You are tired.
      description: They look tired.