The Waffen-SS ("Armed SS") was the combat operations branch of the Schutzstaffel, the Nazi Party militia. Originally limited to recruits from "Aryan" ancestry, membership restrictions were eased beginning in 1940, and by the end of the war units composed entirely of foreign volunteers and/or conscripts were authorized. Nazi racial policy remained at the forefront of membership, however, and groups such as ethnic Poles were forbidden from joining.

Ideological fanaticism was a core component of training, and Waffen-SS units were notorious for near-suicidal aggressiveness, although whether they actually constituted an elite corps is a matter of much post-facto mythologizing. Fully-indoctrinated in the myth of Aryan superiority, they were frequent perpetrators of war crimes and crimes against humanity, and were declared a criminal organization after the war, with non-conscript members denied veterans' benefits.

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Whereas schutzstaffel includes the jet-black Hugo Boss parade dress with Nazi armband, waffen-ss denotes frontline soldiers in camouflage or feldgrau similar to the regular army. It is distinguished from wehrmacht by the style of rank insignia and the presence of the totenkopf on headwear; they also used distinct camouflage schemes at a higher prevalence than their Heer counterparts (eg. the "Stormtrooper" in Company of Heroes is a means of including the Waffen-SS while abiding by censorship laws). If it's World War II and a German soldier is in patterned camo, odds are he's Waffen-SS.