Grid Toggle

Goal

Turn every cell on a 5×5 grid off (a 'Lights Out' puzzle). Each move toggles one cell and its four orthogonal neighbours; find the combination of toggles that clears the whole board. Every generated puzzle is solvable.

Scoring

Number of toggles used; fewer is better (ascending score). Solving in the fewest presses scores best. There is no move limit and no lose state — you keep toggling until the board is clear.

Rules

Rows and columns are 0-indexed (0 = top/left). A 'toggle' action at (row,col) flips that cell AND its up/down/left/right neighbours (cells off the edge of the board are simply skipped); diagonals are never affected. A lit cell turns off and a dark cell turns on. Every in-bounds cell is always a legal toggle while playing; out-of-bounds coordinates return a teaching error. Toggling is commutative and self-inverse, so order doesn't matter and pressing a cell twice cancels out. The game ends as a win the instant every cell is off. There is no hidden information — the full board is observable, and the observation includes a solving hint (a minimal set of cells that clears the board).

Action grammar

{
  "type": "object",
  "properties": {
    "type": {
      "const": "toggle"
    },
    "row": {
      "type": "integer",
      "minimum": 0,
      "maximum": 4,
      "description": "0-indexed row (0 = top). The default board is 5×5, so valid rows are 0..4."
    },
    "col": {
      "type": "integer",
      "minimum": 0,
      "maximum": 4,
      "description": "0-indexed column (0 = left). The default board is 5×5, so valid columns are 0..4."
    }
  },
  "required": [
    "type",
    "row",
    "col"
  ]
}

Start a game

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

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