diff --git a/html/index.php b/html/index.php
index 4900224..2c0c09d 100644
--- a/html/index.php
+++ b/html/index.php
@@ -9,9 +9,13 @@ session_start();
 
 if (isset($_SESSION["game"])) {
     $game = $_SESSION["game"];
+    $engine = $_SESSION["engine"];
 } else {
     $game = Game::fromStartPosition();
+    $engine = new \Engine\Random();
+
     $_SESSION["game"] = $game;
+    $_SESSION["engine"] = $engine;
 }
 
 $content = function() use ($game) {
@@ -22,6 +26,9 @@ if (isset($_GET["move"])) {
     $move = Move::fromJS($_REQUEST["move"]);
     $game->applyInPlace($move);
 
+    $opponentMove = $engine->nextMove($game);
+    $game->applyInPlace($opponentMove);
+
     $content();
 } else {
     require '../src/View/base.php';
diff --git a/src/Engine/Engine.php b/src/Engine/Engine.php
new file mode 100644
index 0000000..3e89f29
--- /dev/null
+++ b/src/Engine/Engine.php
@@ -0,0 +1,10 @@
+<?php
+
+namespace Engine;
+
+use Game\Game;
+use Game\Move;
+
+interface Engine {
+    public function nextMove(Game $game): Move;
+}
\ No newline at end of file
diff --git a/src/Engine/Random.php b/src/Engine/Random.php
new file mode 100644
index 0000000..ac83d73
--- /dev/null
+++ b/src/Engine/Random.php
@@ -0,0 +1,13 @@
+<?php
+
+namespace Engine;
+
+use Game\Game;
+use Game\Move;
+
+class Random implements Engine {
+    public function nextMove(Game $game): Move {
+        $legalMoves = $game->getLegalMoves();
+        return $legalMoves[array_rand($legalMoves, 1)];
+    }
+}
\ No newline at end of file