Frontlines includes a multiplayer mode as well as a single-player campaign that uses the Frontlines system found in the multiplayer component. Single-player mode limits the players to the fictional Western Coalition, while online modes let players play as either the Western Coalition (WC) or Red Star Alliance (RSA). It is not bot compatible. A multiplayer demo of the game was released for the Xbox 360 on February 11, 2008. A demo was also released for the PC. At the end of 2012, the PC online multiplayer mode of the game was no longer available, although the LAN mode still operates.
The gameplay focuses on a central mechanic, the frontline. This is designed to keep the action in one place, by focusing objectives closer together on the battlefield. The frontline also has bonuses. By moving it back and forth across the battlefield, the player may gain or lose weapons and equipment. The frontline mechanic is used in all gametypes, which forces players to choose which objectives they will pursue or defend, adding a strategic level to the gameplay.
The UCAV Drone plays a crucial role in gathering information in real time on the battlefield. The drone reconnoiters enemy units, which are visible through walls, and then show them on the player's HUD and map. Some drones can also be used as a kamikaze bomb, by running them into enemy infantry and self destructing them.
There are four other drones, the Assault Drone, a small treaded vehicle with a mounted Gatling gun, a Mortar Drone, with a mounted four barrelled mortar, an RC drone, which can be packed with C4 and used to destroy armored targets and finally a variant of the UAV drone equipped with anti-infantry rockets.
In an interview, Kaos stated that there would be more than 60 vehicles and weapons in the final game. Airstrikes will also play a large part in gameplay, being an effective way to destroy an opposing force from a distance.
In an interview with developer Joe Halper, Kaos has stated that 32 player multiplayer would be supported for the console version. Near release the maximum player count was raised to 50. The PC version of the game supports 64 players online. Near release it was confirmed that the game would not support cross-platform play, but the developers have stated that they are considering eventually moving the franchise towards becoming a Live Anywhere title.
Frontlines shipped with a total of eight multiplayer maps. These maps range in size and location from a small city block to a solar array over 4 square miles (10 km2) in size. Kaos Studios stated they were looking into releasing extra maps in the future as downloadable content.
This began with the brand new map: "Boneyard". The map was released as a free download on Xbox 360's Marketplace. The map not only offered another well-sized map, but more weapons and vehicles. This included: an all-new Automatic Shotgun, a Carrier Helicopter for the Red Star Alliance, and a "Rocket Jeep".
In addition, the downloadable content clearly stated that this new map was the first of five to be released. The other four maps are named "Sunder", "Wide Awake", "Hind Sight", and "Infiltration". On September 19, Kaos released these maps on Xbox Live. These were later released for the PC as a free download patch.
The game features dedicated servers similar to Battlefield 2: Modern Combat as well as client-side hosting found in the majority of Live-enabled Xbox 360 games. This is done in order to support the 50 player limit, which is unprecedented on the console. The dedicated servers have been shut down of August 31, 2011. Although client-side hosting is still available, servers can only support a 16-player maximum.
Frontlines: Fuel of War is set in 2024, during a global energy crisis, as well as a worldwide avian influenza outbreak. As supplies of oil and natural gas wane, diplomatic relationships between the East and West are strained, causing two new alliances to be formed, the Western Coalition, an evolution of NATO, and the Red Star Alliance, an evolution of the Shanghai Cooperation Organization. Red Star launches a surprise attack on the Western Coalition in retaliation to proof of the Coalition supporting a coup d'état in the oil-rich Red Star member nation Turkmenistanin 2021. As the last oil fields in the Caspian Sea start to go dry, the countries move to secure what resources are left, leading to several small outbreaks that turn quickly into full-scale war.
The player steps in the shoes of the members of a violent and battle-hardened Western Coalition strike force nicknamed the "Stray Dogs" that are to spearhead assaults against defensive positions of Red Star across Central Asia and Eastern Europe, as Red Star tries to secure resources in the best of worldwide interest. The Stray Dogs are joined by Wayne Andrews, a reporter for the Affiliated Press, throughout the game.
The game ends after the final mission entitled "History Repeats," upon bringing the Russian ministry to a collapse and cutting the nation off from the rest of the world by destroying a satellite uplink. As pockets of resistance are hunted down by Coalition forces, a questionable future is proposed by Andrews, stating that the Russians are forming a government in exile, and Chinese troops are amassing on the border. In the final cutscene, Andrews states that he wishes to live to see humanity being anew. The game ends by showing Red Star fighter jets opening fire on Andrews, leaving the story open for a sequel.
- Xbox 360 Collector's Edition (UK, AU, Denmark, NZ)
- Art Book
- Bonus disc with music, behind-the-scenes videos, etc
- PC Collector's Edition (UK, AU, NZ)
- PC Collector's Edition (Denmark)
- Art book
- CD soundtrack
- GameStop/Best Buy Pre-Order Bonus (NA)
- Circuit City (NA)
- CD soundtrack
- Limited-edition collector's tin