diff --git a/.eslintrc.json b/.eslintrc.json
new file mode 100644
index 0000000..3d86fcb
--- /dev/null
+++ b/.eslintrc.json
@@ -0,0 +1,28 @@
+{
+  "env": {
+    "browser": true,
+    "es2021": true,
+    "node": true
+  },
+  "extends": "eslint:recommended",
+  "parserOptions": {
+    "ecmaVersion": "latest",
+    "sourceType": "module"
+  },
+  "rules": {
+    "indent": ["error", 4],
+    "linebreak-style": ["error", "unix"],
+    "quotes": ["error", "single", { "avoidEscape": true }],
+    "semi": ["error", "always"],
+    "no-unused-vars": ["warn", { "argsIgnorePattern": "^_" }],
+    "no-console": "off",
+    "no-debugger": "warn"
+  },
+  "ignorePatterns": [
+    "node_modules/",
+    "coverage/",
+    "dist/",
+    "build/",
+    "*.min.js"
+  ]
+}
diff --git a/js/engine/MoveValidator.js b/js/engine/MoveValidator.js
index 754124e..6dd348c 100644
--- a/js/engine/MoveValidator.js
+++ b/js/engine/MoveValidator.js
@@ -226,8 +226,8 @@ export class MoveValidator {
 
         // King can't pass through check
         for (let col = king.position.col + direction;
-             col !== targetCol + direction;
-             col += direction) {
+            col !== targetCol + direction;
+            col += direction) {
 
             const simulatedBoard = board.clone();
             simulatedBoard.movePiece(king.position.row, king.position.col, row, col);
diff --git a/js/engine/SpecialMoves.js b/js/engine/SpecialMoves.js
index 7852317..a0b50b7 100644
--- a/js/engine/SpecialMoves.js
+++ b/js/engine/SpecialMoves.js
@@ -155,20 +155,20 @@ export class SpecialMoves {
 
         let newPiece;
         switch (pieceType) {
-            case 'queen':
-                newPiece = new Queen(color, { row, col });
-                break;
-            case 'rook':
-                newPiece = new Rook(color, { row, col });
-                break;
-            case 'bishop':
-                newPiece = new Bishop(color, { row, col });
-                break;
-            case 'knight':
-                newPiece = new Knight(color, { row, col });
-                break;
-            default:
-                newPiece = new Queen(color, { row, col });
+        case 'queen':
+            newPiece = new Queen(color, { row, col });
+            break;
+        case 'rook':
+            newPiece = new Rook(color, { row, col });
+            break;
+        case 'bishop':
+            newPiece = new Bishop(color, { row, col });
+            break;
+        case 'knight':
+            newPiece = new Knight(color, { row, col });
+            break;
+        default:
+            newPiece = new Queen(color, { row, col });
         }
 
         board.setPiece(row, col, newPiece);