"Fatal Alliances: The Great War 1914-1918" is a World War I version of World in Flames. Like its predecessor, Fatal Alliances is all encompassing and represents every theater and aspect of the First World War. Fatal Alliances expands upon the military system of World in Flames to highlight the diplomatic and civilian fronts.

When we think of the First World War, we often think of miles of static trenches stretching along the Western Front. Indeed trench warfare was a huge component of the war, but many theaters in the Middle East, Russia, the Balkans, and even Africa were very dynamic – as even the Western Front was at times. Moreover, Fatal Alliances focuses on the major technological changes the war brought on, on land, at sea, and in the air. In order to prevail on the battlefield, you must coordinate artillery, elite ace-led air forces, gas units, shock troops, engineering units, infantry, cavalry, and early tanks.

The First World War was truly global, and in Fatal Alliances, the Eastern Front, the Middle East, the Caucasus, Africa, and even Asia and the Americas play a major role. German forces are loose in Africa, and South Africa's loyalty is uncertain. Italy will go to the highest bidder. The Ottomans face Russians in the Caucasus and British Forces along the Suez Canal. China is in turmoil, and could potentially join either side. Japan is nominally an Ally, but Japanese expansionism is already at odds with the interests of other Allied powers. Russia is primed for revolution, with Bolsheviks facing Tsarist forces in a battle for control of the largest swath of land in Eurasia.