What You Need for Travel
When traveling light, your rucksack might be your only luggage. It could also be used as a carry-on piece for airline or rail travel. If the rucksack is your only luggage, pack clothes, undergarments, toiletries, camera, a small laptop computer, travel documents and small kits for repairs to your clothing and medicinal supplies. To use a rucksack as a carry-on, pack items you'll use during travel, such as a book, your computer and any work you're bringing with you. The rucksack is a good place to carry bulky, but lightweight items, such as a blanket, sleeping bag or your coat. In this case, your rucksack can double as a pillow for car or train travel.
What You Need for Hiking
When packing a rusksack for hiking, take into consideration what you'll be doing, where you'll be going and how long you'll be staying. You'll have to carry your pack with you, maybe over long distances, so keep it as light as possible. Pack a sleeping bag that's as light as you can get away with for the climate. Pack clothing that suits the weather. Add, too, a small tent, food and water, a medical kit, your cell phone and any necessary equipment. Don't forget clean, dry socks.
What You Need for Deployment
Packing for deployment means you'll have a rucksack besides other luggage. If that's the case, don't pack your clothing in your rucksack. Things to consider packing include toiletries, your papers and identification, your cell phone and other electronics, a medical kit, a small amount of food and water and a change of clothes. Should you become separated from the rest of your gear for a while, you'll have what you need.
Rucksack Safety
Carrying a rucksack requires attention to safety. Packing properly ensures you don't hurt yourself carrying a heavy bag. Pack the heaviest items in the middle of the pack where they will rest close to your back. This relieves some of the pressure when you're carrying it. Watch the weight of your bag as well. Wear it around packed full so you can handle the weight. Consider, too, the prospect of theft. Since the pack is behind you, it's easier for someone to steal from the outer pockets. Keep things like dirty socks and rolls of toilet paper in these pockets. Place valuable items deeper in the rucksack.