'Grosser Schlag' was the German overall plan for the use of massed night-fighter forces to tackle the streams of heavy bombers used by Air Chief Marshal Sir Arthur Harris’s RAF Bomber Command during their night attacks on German cities and towns (6 November 1944 onward).

The German intent was to commit so many night-fighters that, in concert with the fire of radar-directed anti-aircraft guns, the British would lose anything between 400 and 500 bombers in a loss rate that would cause then to end their night bombing effort.