Battlefield 3 is an online first-person shooter developed by DICE that focuses on large-scale modern warfare combining infantry and vehicles. It emphasizes teamwork and strategies. The game introduces a class and squad system where players can work together in squads of 4 from their team. The strategy guide will introduce and explain the classes, squad system, vehicles, and advanced tactics. It will analyze the 4 character classes - Assault, Engineer, Support, and Recon - which each have unique abilities, gadgets, and weapons. The Assault class focuses on infantry combat and reviving teammates. The Engineer class is designed to destroy vehicles with anti-armor weapons and repair friendly vehicles.