What are some common beginner mistakes to avoid when programming a game in PHP?

One common beginner mistake when programming a game in PHP is not properly sanitizing user input, which can lead to security vulnerabilities such as SQL injection or cross-site scripting attacks. To avoid this, always validate and sanitize user input before using it in your game.

// Sanitize user input using filter_var
$user_input = filter_var($_POST['user_input'], FILTER_SANITIZE_STRING);