{
  "format": "duck-pack/0",
  "id": "design-a-level",
  "name": "Design a level",
  "grades": "6 to 8",
  "grade_from": 6,
  "grade_to": 8,
  "vocabulary": "r001",
  "license": "CC-BY-4.0",
  "credit": "Duck Cards, from microduckstudio.com",
  "about": "Every card, a six by six board and your own Your cards: study three worked levels, then write one for another group and prove its par.",
  "cards": [
    "start",
    "end",
    "walk_forward",
    "walk_backward",
    "turn_left",
    "turn_right",
    "stop",
    "slow",
    "fast",
    "look_left",
    "look_right",
    "look_up",
    "look_down",
    "straight",
    "kick_left",
    "kick_right",
    "sit_or_stand",
    "roll",
    "peck_ground",
    "greet",
    "chirp",
    "coo",
    "alarm",
    "wheee",
    "repeat",
    "end_repeat",
    "when_falls",
    "card_1",
    "card_2",
    "card_3",
    "card_4",
    "card_5",
    "card_6",
    "card_7",
    "card_8",
    "card_9"
  ],
  "score": "cards",
  "board": {"columns": 6, "rows": 6, "square_cm": 30, "duck_square_cm": 30, "duck_square_source": "duckbench simulator (Pollen's MJCF, alpha_walking), 2026-10-15, with a first spec past Pollen's pad envelope; the shipped spec is not measured yet, so on a real duck Walk and Turn cards are timed until Pollen's duck-sim and a tester's duck pass (docs/PACKS.md, Acceptance)"},
  "challenges": [
    {
      "id": "design-1",
      "name": "Stairs to the nest",
      "start": {"at": [0, 5], "facing": "north"},
      "goal": [4, 1],
      "walls": [
        {"between": [[0, 4], [0, 3]]},
        {"between": [[1, 3], [1, 2]]},
        {"between": [[2, 2], [2, 1]]},
        {"between": [[3, 1], [3, 0]]}
      ],
      "gates": [
        {"at": [1, 4], "axis": "ew"},
        {"at": [2, 3], "axis": "ew"},
        {"at": [3, 2], "axis": "ew"},
        {"at": [4, 1], "axis": "ew"}
      ],
      "finish_with": null,
      "par": 3,
      "solution": [{"card": "repeat", "times": 4}, {"card": "card_1"}, {"card": "end_repeat"}],
      "buggy": null,
      "hint": "Card 1, Stair step, is four cards in one. How many stairs are there?"
    },
    {
      "id": "design-2",
      "name": "Round the big pond",
      "start": {"at": [0, 5], "facing": "north"},
      "goal": [0, 5],
      "walls": [
        {"between": [[1, 0], [1, 1]]},
        {"between": [[1, 4], [1, 5]]},
        {"between": [[2, 0], [2, 1]]},
        {"between": [[2, 4], [2, 5]]},
        {"between": [[3, 0], [3, 1]]},
        {"between": [[3, 4], [3, 5]]},
        {"between": [[4, 0], [4, 1]]},
        {"between": [[4, 4], [4, 5]]},
        {"between": [[0, 1], [1, 1]]},
        {"between": [[4, 1], [5, 1]]},
        {"between": [[0, 2], [1, 2]]},
        {"between": [[4, 2], [5, 2]]},
        {"between": [[0, 3], [1, 3]]},
        {"between": [[4, 3], [5, 3]]},
        {"between": [[0, 4], [1, 4]]},
        {"between": [[4, 4], [5, 4]]}
      ],
      "gates": [
        {"at": [0, 1], "axis": "ns"},
        {"at": [4, 0], "axis": "ew"},
        {"at": [5, 4], "axis": "ns"},
        {"at": [1, 5], "axis": "ew"}
      ],
      "finish_with": null,
      "par": 3,
      "solution": [{"card": "repeat", "times": 4}, {"card": "card_2"}, {"card": "end_repeat"}],
      "buggy": null,
      "hint": "Card 2, Side of the pond, walks one whole side and turns the corner."
    },
    {
      "id": "design-3",
      "name": "Kick from the island",
      "start": {"at": [0, 5], "facing": "north"},
      "goal": [5, 0],
      "walls": [
        {"between": [[0, 4], [0, 3]]},
        {"between": [[1, 3], [1, 2]]},
        {"between": [[2, 2], [2, 1]]},
        {"between": [[3, 3], [4, 3]]},
        {"between": [[4, 2], [4, 1]]}
      ],
      "gates": [{"at": [3, 2], "axis": "ew"}],
      "finish_with": "kick_right",
      "par": 4,
      "solution": [
        {"card": "repeat", "times": 5},
        {"card": "card_1"},
        {"card": "end_repeat"},
        {"card": "kick_right"}
      ],
      "buggy": null,
      "hint": "The class that wrote this level first said par was 9: three stairs to the bridge, then along the top. Look at where the stairs would go if they kept going."
    }
  ],
  "lessons": [
    {
      "title": "Name a routine",
      "skill": "Your cards",
      "body": "Study Stairs to the nest. Stair step is a Your card: four printed cards saved under one number. Write out every card that Repeat 4, Stair step, End repeat stands for, and count how many cards it saves.",
      "ask": "What makes a run of cards worth saving as a Your card?"
    },
    {
      "title": "Write a level for another group",
      "skill": "Authoring",
      "body": "Each group draws a six by six board on squared paper: a start square and facing, a goal, up to six walls, one or two gates, and a finish card if you like. Write a row that solves it and count its cards. That count is your par. Trade boards with another group and play theirs.",
      "ask": "What did the other group find hard about your level that you did not expect?"
    },
    {
      "title": "Prove your par",
      "skill": "Checking par",
      "body": "Kick from the island was first written with par 9; another group solved it with 4 by letting the stairs keep going. Before trading a level, try hard to beat your own par. If someone else beats it, the par was wrong, not the players, so change the number.",
      "ask": "How could you be sure no shorter row exists?"
    },
    {
      "title": "Steps par by hand",
      "skill": "Search",
      "body": "A steps par can be found for certain: from the start, mark every square the duck can reach in one step, then two, then three, like ripples on a pond, until the goal is marked. Do it for one level on paper, then compare with the par the pack's checker computed.",
      "ask": "Why is a steps par easier to be sure of than a cards par?"
    },
    {
      "title": "When it falls",
      "skill": "Events",
      "body": "Add a When it falls row to your solution: what the duck does once it is back on its feet. The board does not play it, but a duck running your row would. Test it by having the student playing the duck sit down when you say fall.",
      "ask": "Should the duck carry on after a fall, or go back to the start?"
    }
  ],
  "yours": [
    {
      "tag": 200,
      "code": "card_1",
      "name": "Stair step",
      "category": "yours",
      "kind": "yours",
      "plan": null,
      "does": "Walk forward, turn right, walk forward, turn left: one step up a stair.",
      "row": [
        {"card": "walk_forward"},
        {"card": "turn_right"},
        {"card": "walk_forward"},
        {"card": "turn_left"}
      ]
    },
    {
      "tag": 201,
      "code": "card_2",
      "name": "Side of the pond",
      "category": "yours",
      "kind": "yours",
      "plan": null,
      "does": "Walk forward five times, then turn right.",
      "row": [
        {"card": "repeat", "times": 5},
        {"card": "walk_forward"},
        {"card": "end_repeat"},
        {"card": "turn_right"}
      ]
    }
  ]
}