What are common pitfalls to avoid when using PHP scripts in a browser game environment?

One common pitfall to avoid when using PHP scripts in a browser game environment is exposing sensitive information or vulnerabilities through insecure coding practices. To prevent this, always sanitize user input and validate data to prevent SQL injection attacks or other security risks.

// Example of sanitizing user input in PHP
$user_input = $_POST['user_input'];
$clean_input = filter_var($user_input, FILTER_SANITIZE_STRING);