In a non-worst case scenario (we are talking about 98% of the time) this bag, along with your daily carry bag (DON'T forget to grab your daily carry bag when you grab your BOB) will see you through any number of minor emergencies (in fact I have never used my BOB in a zombie apocalypse attack but I have used it on many occasions--everything from an overnight stay in the ER two hours away from home with a friend, to an impromptu weekend stay in the wilderness, to retrieving random items out of it because someone needed a specific item and I just happened to have said item in my BOB).
Also, where you keep your BOB is important. I usually keep my BOB in my vehicle for the simple fact that my vehicle is always with me whether I am at home or at work. You may want to put your BOB in a closet in your home, in your office, etc. Or you may want to make BOBs for your home, car, AND office.
Here's what you need in your BOB (feel free to add or subtract items to meet your needs):
- Backpack (I prefer a quality yet generic looking backpack over something camo simply because it blends in better to the urban/suburban environment which I am most likely to be in).
- Complete change of clothing (shoes, sox, underwear, pants, t shirt, long sleeve shirt, sweater, jacket, poncho)
- Toiletry kit (soap, razor, shampoo, toothbrush, toothpaste, mirror, floss, comb, wet wipes, tissue packets, deodorant, nail clippers, nail file, sunblock, toilet paper, small quick-dry towel)
- Shelter (very compact sleeping bag, very compact tent. Some people may prefer a tarp and some paracord along with a fleece blanket; I like a bit more comfort than that)
- Useful stuff in a disaster: work gloves, goggles, breaker bar, bandanna, fluorescent strip of cloth, whistle, bug juice, para cord, tarp, large plastic garbage bags, compass, map
- Electronics: wind-up radio, flashlight, HAM radio, batteries for all of these things
- First aid kit: as comprehensive as you can find/make; include vitamins, meds, acidophilous pills, prescription meds, and prescription-level medications if possible (pain killers, antibiotics, etc)
- A small bag of useful things: rubber bands, safety pins, Sharpie marker, pen, paper, playing cards, ziploc bags, sewing kit, matches, lighter, scissors, duct tape.
- Food (enough food for three days that is simple to cook or requires little cooking). Ideas include dried soup, jerky, candy, instant rice, foil-packed meats (tuna, chicken), sardines, peanut butter, oatmeal, energy bars, nuts, instant coffee packets, packets of sugar/salt/ketchup/hot sauce, dried fruit, etc.
- Nice to have things: stove, mess kit, eating utensils, fishing kit, water purification tablets, emergency blanket, water filter, can opener, snare wire
- Protection: firearm, extra ammo, cleaning kit; fixed-blade knife
- Office stuff: cash, copy of all important documents, list of emergency contacts, passport
- Don't forget to add items specifically needed in your area (cold weather gear in the north, a head net in tropical areas).
- Don't forget to add items that you specifically need (female hygiene items, hearing aid batteries, spare pair of glasses, etc).
- Don't forget that you don't want to look like Rambo. You will most likely be using your BOB in a suburban/urban environment so breaking out enough stuff to stock a FEMA shelter will be...telling. You want to look like a guy carrying his backpack to work not like a guy prepared to do battle in Afghanistan.
- Don't look like you have a lot of good stuff that someone else may want to steal from you. Blend in, look ordinary, and keep all of your stuff bagged up and away from prying eyes until you are in a safe location.
- Don't forget to buy quality items. Cheap crap is just that...cheap crap that is much more likely to break when you need it most.
- Don't pack a hundred pound of crap. In most urban/suburban environment, even rural environments in many cases, you will be able to acquire the stuff you need. You don't need to bring stuff for every possible no-matter-how-remote contingency.
- Don't think you even need as much stuff as I have on my list above. I've seen plenty of refugees travel for weeks and many, many miles with as many items as you can carry in a small plastic supermarket bag. 90% of the stuff on this list is a luxury.
- Don't forget that if you don't see an item on this list (pocket knife, cell phone) it is because you should have that item in your daily carry bag (which you will be carrying with you as well).