Fernford

Goal

Guide a fox kit north to the home glade. The board is 7 columns (0 left to 6 right) and rows 0 (start) to 150 (home glade); you begin at row 0, col 3. The world is frozen until you act: each accepted action advances every vehicle, every driftwood float and the mist schedule by exactly one tick. Reach any cell of row 150 to win. The run ends early if a vehicle catches the fox, the fox stands in open water, or the rising mist reaches the fox's row. Score as much as you can either way: new rows, streaks, pickups and milestones all pay.

Scoring

New furthest row reached: +10 (only when your best row increases; back-and-forth pays nothing). Streak: consecutive accepted actions that EACH reach a new furthest row add a growing bonus on top of the +10: the 3rd in a row +5, 4th +10, 5th +15, capped at +25 extra per row; any wait, sideways, backward or non-advancing action resets the streak to 0. Pickups (each collectable once, marked on the map until taken): firefly +25, glowmoth +100 (always on road cells), dewdrop +15 plus a shield (max 1 held; a dewdrop taken while shielded still pays +15). Milestone: +50 the first time you reach each of rows 10, 20, ... 140. Home glade (row 150): +500. The score never decreases.

Rules

ROWS. Each row is one of: meadow (safe; may hold up to 3 static blockers you cannot enter), road (vehicles of length 1-2 slide dir x speed cells every tick; speed is 1 or 2 and all vehicles in a row share direction and speed), brook (driftwood floats of length 2-3 slide 1 cell every tick; standing on driftwood is safe and carries you, open water is fatal), or home (row 150, always safe). Lanes wrap modulo 7, so a lane's pattern repeats every 7 ticks: a vehicle or float occupying column c at tick t occupies (c + dir x speed) mod 7 at tick t+1. Rows 0-1 are open meadow and the two rows after every milestone row are meadow. ACTIONS. Exactly two: {type:'hop', dir: up|down|left|right} moves one cell (up = toward row 150) and {type:'wait'} stays in place. Every accepted action advances the world one tick. An invalid action (hopping off columns 0-6, below row 0, into a meadow blocker, or into a row at or below the mist row) is refused with ok:false and costs nothing: no tick passes and the state is unchanged. Hopping into a vehicle or open water IS accepted (and usually fatal), so read the lanes first. TICK ORDER (exact): (a) your displacement is applied; (b) arrival check: a vehicle in the destination cell ends the run (caught) unless a shield absorbs it (the shield is consumed and the fox is untouchable for the rest of this tick); on a brook cell the float under the fox is noted, and no float means swept unless a shield absorbs it (the fox treads water this tick and must reach driftwood or a bank with its next action); (c) any uncollected pickup in the cell is collected; (d) the world advances one tick and a fox standing on a float moves with it, including wrapping across the board edge; (e) post-move check: a vehicle now in the fox's cell, or a speed-2 vehicle that passed through the fox's cell this tick (the skipped middle cell of a 2-cell move is lethal), means caught unless shielded; a brook cell with no float under the fox means swept unless shielded; (f) the mist counter falls by 1, and at 0 the mist row rises by 1 and the counter resets to the interval of the band the mist row is in; if the mist row reaches the fox's row the run ends (misted; shields never stop the mist); (g) scoring: a new furthest row pays +10 plus the streak bonus, milestone rows pay +50, and row 150 pays +500 and wins. MIST. The mist starts at row -3 and rises on a fixed schedule that depends only on the tick: the interval is 9 ticks per row while the mist row is at or below row 10, then 8 (rows 11-30), 7 (rows 31-60), 6 (rows 61-100) and 5 (rows 101-149). Rows at or below the mist row cannot be entered. DIFFICULTY. Row bands tune generation: rows 1-10 meadow 60% / road 40% (all speed 1); 11-30 45/40/15 with 10% speed-2 roads; 31-60 35/40/25 with 25%; 61-100 30/40/30 with 40%; 101-149 25/40/35 with 55%. Generation guarantees passable lanes (minimum gaps between vehicles, float coverage of at least 4 of 7 cells, capped runs of consecutive hazard rows). Everything is seeded and deterministic: the observation shows true positions and the whole run is a pure function of the seed and your actions.

Action grammar

{
  "oneOf": [
    {
      "type": "object",
      "properties": {
        "type": {
          "const": "hop"
        },
        "dir": {
          "enum": [
            "up",
            "down",
            "left",
            "right"
          ]
        }
      },
      "required": [
        "type",
        "dir"
      ]
    },
    {
      "type": "object",
      "properties": {
        "type": {
          "const": "wait"
        }
      },
      "required": [
        "type"
      ]
    }
  ]
}

Start a game

curl -s "https://gameboard.gg/api/games/fernford/init?seed=7"

Then POST { state, action } to https://gameboard.gg/api/games/fernford/action, carrying state forward each call. See the API overview for the full loop.