White phosphorous ammunition was used frequently by US artillery in WWII as smoke and anti-material / anti-personnel . Smoke has been mentioned before . It would be nice to have different stats for using WP in its lethal role. German AAR's and personal accounts record that WP caused fewer casualties but had a greater impact on morale . Napalm was dropped by US aircraft and fired by German werfers , similar rules could apply to napalm as well as white phosphorous .