A three-day assault bag should contain supplies that will keep you going for 72 hours off-grid. This should include emergency shelter, navigation equipment, tools such as a leatherman, torch, extra water or filters, cords, a lighter or flint, calorie-dense food, a first-aid kit, basic toiletries including toilet paper, and extra clothing including socks. Of course, you'd also want additional equipment specific to your activity. As such, the military would need extra ammunition and communication devices, climbers would require climbing apparatus, and hunters would need a weapon and ammunition.