diff --git a/LightsOutGame.java b/LightsOutGame.java
index a1935da..9caffa7 100644
--- a/LightsOutGame.java
+++ b/LightsOutGame.java
@@ -1,16 +1,34 @@
+import java.io.InputStream;
 import java.util.Optional;
 
 /**
  * A logic puzzle where each cell on a grid can be either "on" or "off".
  * Selecting a cell toggles it and its immediate neighbors.
  * The goal is to turn all the lights off in as few moves as possible.
- * <pre>
- * Consider a model using a grid of booleans.
- * Implement toggling logic on that grid.
- * </pre>
  * @version 1
  */
 class LightsOutGame implements Game {
+    static int DEFAULT_BOARD_SIZE = 5;
+    private LightsOutBoard board;
+    private InputStream inputStream;
+
+    // Default constructor
+    public LightsOutGame() {
+        this(System.in);
+    }
+
+    // Constructor with InputStream injection for testing
+    public LightsOutGame(InputStream in) {
+        this.inputStream = in;
+        this.board = new LightsOutBoard(DEFAULT_BOARD_SIZE, DEFAULT_BOARD_SIZE);
+    }
+
+    // Constructor with InputStream and board injection for deterministic testing
+    public LightsOutGame(InputStream in, LightsOutBoard board) {
+        this.inputStream = in;
+        this.board = board;
+    }
+
     @Override
     public String getName() {
         return "Lights Out";
@@ -25,6 +43,99 @@ public Optional<Integer> play() {
         System.out.println("Turning them 'off' or 'on' as well.");
         System.out.println("Grid must be lit in as few turns as possible.");
         System.out.println("Good luck!");
+        
+        // TODO: Implement game loop (Task #91)
+        // - Randomize board
+        // - Display board
+        // - Get user input
+        // - Toggle cells
+        // - Check win condition
+        // - Handle quit/restart
+        
         return Optional.empty();
     }
+
+    /**
+     * Nested inner class representing the Lights Out game board.
+     * Holds the grid and toggling logic.
+     */
+    static class LightsOutBoard {
+        private boolean[][] grid;
+        private int numRows;
+        private int numColumns;
+
+        // Constructor with dimensions
+        public LightsOutBoard(int numRows, int numColumns) {
+            this.numRows = numRows;
+            this.numColumns = numColumns;
+            this.grid = new boolean[numRows][numColumns];
+            // TODO: Initialize grid (all off by default)
+        }
+
+        // Copy constructor
+        public LightsOutBoard(LightsOutBoard other) {
+            this.numRows = other.numRows;
+            this.numColumns = other.numColumns;
+            this.grid = new boolean[numRows][numColumns];
+            // TODO: Deep copy the grid from other
+        }
+
+        /**
+         * Toggles specified cell and its neighbors.
+         * @param row the row index (0-based)
+         * @param column the column index (0-based)
+         * @return true if toggle was successful, false otherwise
+         */
+        public boolean toggle(int row, int column) {
+            // TODO: Implement toggle logic (Task #91)
+            return false;
+        }
+
+        /**
+         * Returns ASCII board display with row/column labels.
+         * @return String representation of the board
+         */
+        public String display() {
+            // TODO: Implement display logic (Task #91)
+            return "";
+        }
+
+        /**
+         * Gets the state of a cell.
+         * @param row the row index
+         * @param column the column index
+         * @return true if light is on, false if off
+         */
+        boolean getCell(int row, int column) {
+            // TODO: Implement getter (Task #91)
+            return false;
+        }
+
+        /**
+         * Sets the state of a cell.
+         * @param row the row index
+         * @param column the column index
+         * @param value true to turn on, false to turn off
+         */
+        void setCell(int row, int column, boolean value) {
+            // TODO: Implement setter (Task #91)
+        }
+
+        /**
+         * Checks if all lights are off.
+         * @return true if all lights are off, false otherwise
+         */
+        boolean allOff() {
+            // TODO: Implement win condition check (Task #91)
+            return false;
+        }
+
+        /**
+         * Randomizes the board state.
+         */
+        void randomize() {
+            // TODO: Implement randomization logic (Task #91)
+        }
+    }
 }
+