139.M41; Abaddon the Despoiler, Warmaster of the Black Legion and greatest Champion of Chaos Undivided, rallies the forces of Chaos under his command and launches a chain of surprise attacks against Imperium worlds in the Gothic Sector. The 12th Black Crusade of Abaddon the Despoiler, which will soon be infamously known as the Gothic War, has just begun.

The game's extensive campaign follows the events of this Gothic War. You are Admiral of a Battlegroup belonging to Battlefleet Gothic, charged with the protection of the Imperium in the Gothic Sector. Your Battlegroup is the first line of defence against the sudden and merciless offensive of the Chaos Warfleet. Do not fail the God-Emperor, and drive Abaddon and his cohort back into the Eye of Terror. The fate of Mankind lies within your hands.

The campaign of Battlefleet Gothic is dynamic, with critical missions branching to different outcomes depending on the success – or failure – of your missions. The Gothic Sector is ever-evolving, with new threats appearing and launching strikes on Imperium worlds, allies requesting help... Quite often, multiple events will arise simultaneously, requiring you to make critical decisions bearing important consequences, such as on your access to resources or available allies; and, ultimately, on the unfolding of the war itself.

Destroy the enemy fleet, escort a convoy, protect a naval base from an assault, recover critical data from an enemy ship, prevent an Exterminatus or simply survive to see another day... the missions in the campaign of Battlefleet Gothic are varied and thrilling.
Hold the Gothic Sector
Across the void of known space, enemies of the Imperium are legion, lurking and awaiting an opportunity to strike its planets and territories. Every sector must be held by local fleets in order to defend the Emperor's systems and loyal subjects.
Imperial soldiers gone rogue will try to take systems from you. These traitors are not part of any threat, but lost systems will give you penalties depending on the system's type nonetheless.
Ork Threat
Orks have been detected in the Sector! They will fight to take planets from you. Be aware that any system under their control will give you penalties depending on the system's type, and make them more aggressive.
Eldar Threat
The Eldar finally unveil their presence and attack Imperial worlds! They will fight to take planets from you. Be aware that any system under their control will give you penalties depending on the system's type, and make them more aggressive.
Chaos Threat
Massive Chaos forces are invading the whole sector and attack with violence! Admiral, do your best to keep up with them and defeat the Chaos armada! They will try to take your worlds. Be aware that any system under their control will give you penalties depending on the system's type, and make them more aggressive.
Each world has its own benefits.
If you lose more than 50 systems, the Gothic sector will be lost and you'll lose the game.
Worlds' Properties
Basic Product Worlds
Hive Worlds provide the manpower, Agri-Worlds supply the food, and Mining Worlds hand over minerals that allow the Imperium of Mankind to subsist through time and space.
Each Basic Product World lost reduces Renown earned by 1%
Hive World
Hive Worlds are huge planets colonized for the sole purpose of housing the loyal followers of the Emperor. Constellated with humongous Hives that shelter millions of lives, they are the recruiting grounds of the Imperium.
Entirely dedicated to producing meat and vegetables for other worlds, Agri-Worlds are the cellars of the Imperium, and as such, make a valuable target for its enemies: whether dying from war or starvation a man will still end up dead.
Mining World
To sustain such war efforts across the galaxy, the Imperium investigate any floating rock and planetoids rich in minerals and strip them of their precious resources used to make the bullets that feed the guns and the walls that protect the men.
Schola Progenium
Under the rule of the Adeptus Ministorum, planets called Schola Progenium shelter vast complexes in which next generations of Imperial officers and administrators are trained.
Each Schola Progenium lost reduces Captain Experience gains by 5%
Portal Worlds
Placed in adequate places, and used frequently enough to provide "safer" ways through the Warp for fleets, Portal Worlds are a vital asset for anyone wishing to be able to move quickly and efficiently across the territory.
Each Portal World lost reduces the chances of a bonus Deployment by 3%
Space Stations
Humongous structures fitted to support and refuel entire warfleets during their travels across the galaxy, Space Stations are equipped in all kinds of equipment facilitating vessel maintenance.
Each Space Station lost increases Repair costs by 5%.
Cardinal Worlds
Considered sacred ground and classified as Shrine worlds, these planets are entirely dedicated to the Imperial Cult and often oversee the Ecclesiarchy's hierarchy in the sector. They are a testimony to the Emperor's power itself.
Penalty: For each Cardinal World lost, Sedition chances are increased.
Penal Worlds
Concentrating every criminal from every planet in a sector results in a Penal World where the worst of the Imperium end. They are not beyond redemption unlike Chaos servants and are often given a chance to repent through service in the penal legions against mankind's enemies.
Each Penal World lost gives you -3% to the Troop value of all ships.
Inquisitorial Bastions
Planets reclaimed by the Inquisition to gain a forward base in their struggle against the enemy of mankind.
A successful mission on that world grants you a Reputation point for the Inquisition, which reduces their favour cost.
Omnissiah Temples
More than just Forge Worlds, Temples of the Omnissiah are sacred to the Tech-Priests, and are home to their most secret rituals.
A successful mission on this world grants you a Reputation point for the Adeptus Mechanicus, which reduces their favour cost.
Reputation with this faction reduces the cost of their favour.

You can now use your Renown to grant your Line Ships the help of one of the four factions of the Imperium. Favours give unique Skills and Upgrades to your ship.

Helping the Space Marines and Imperial Navy fleets winning a battle reduces the cost of their favours.

Successfully defending Omnissiah Temples and Inquisition Bastions reduces the cost of their favours.
Adeptus Astartes
The Adeptus Astartes are one of the most elite and feared forces of the Imperium of Man. There are far too few Space Marines to form the Imperium's main military forces; instead they operate as highly mobile strike forces.
The Inquisition
The Inquisition are the powerful secret agents of the Imperium responsible for guarding the souls of humanity. The purpose of the Inquisition is to identify and destroy the myriad of potential threats to the Imperium and humanity.
Adeptus Mechanicus
The Adeptus Mechanicus is a technological organisation which holds a monopoly on technological knowledge in the Imperium. Their Forge Worlds turn out the Imperium's most powerful and advanced weaponry and equipment.
Imperial Navy
The Imperial Navy is one of the armed forces employed by the Imperium. The Imperial Navy is responsible for the fleets of warships that soar between the stars and planets in the Imperium as well as engaging threats both inside and outside the Imperium's borders.
Some Artefacts are coveted by the Chaos forces. Securing them now might prove useful later. Anything the enemy wants is worth taking away from him.