The battlecruiser Ersatz Yorck was initially designed as the second vessel of the Mackensen-class large cruisers, intended to replace German cruisers lost in the first two years of World War One. She was laid down at the Vulcan Yard in Hamburg in July 1916 and was originally planned to carry 35 cm guns. However, her design underwent significant revisions in response to the combat performance of the British Repulse-class and reports concerning the American Lexington-class battlecruisers. The resulting design, designated GK6, upgraded the main guns to 38 cm, improved the armour, removed some secondary guns and torpedo tubes, and featured a distinctive single large funnel. Three vessels of the new class were subsequently ordered as part of a new war programme. Ersatz Yorck, still in an early phase of construction, was to be the first of the three, with completion scheduled for 1919. Yet, as 1917 was coming to an end, it became increasingly clear that resource shortages, manpower constraints, and the strategic realities after the Battle of Jutland made further work on the vessel pointless. All construction ceased before the end of the year, and the remains of the vessel were dismantled by early 1920.

Introduced in Update "Storm Warning", Ersatz Yorck is the first German battlecruiser to mount 15-inch-equivalent main guns. She shares her primary armament with the Bayern-class battleships, and trades improved speed for lower survivability. Her eight 38 cm main guns are supplemented by 150 mm secondaries, sufficient to counter enemy cruisers, and a relatively weak anti-aircraft complement consisting of eight single-mount 88 mm guns. Like most World War One-era vessels, Ersatz Yorck is most vulnerable to aerial attack; even strategic bombers can approach and destroy her with relative ease. In direct gun fights, she is most susceptible to plunging fire—at ranges exceeding 10 km, even some light cruisers can penetrate into her magazines. Nevertheless, she is a very dangerous combatant, and her 38 cm main guns can wreak havoc on most enemies in her battle rating.