from the perspective of preparedness rather than sport the requirements of a back are somewhat different. For the short term interruptions of normal that we discuss here (this is not a survivalist site) the use of a back pack would be primarily to carry enough essentials to get out of reach of the disaster or to the shelter and help you make it through until help arrives. For this pupose capacity is more important that weight or comfort. When considering "bugging out" likely scenarios that are not TEOTWAWKI include hazmat spills, storms and floods. With proper planning we should be able to take a vehicle out of such situations. Most other scenarios are more likely to result in "bugging in" If you pack your bug-out bag in a set of cargo packs that can be carried by your family (one each) for a few miles and add to that a small boat and bicycles and keep them near the 4X4 in a shed or if too urban for the shed keep the packs in the garage or 4X4 then you will be ready to grab-n-go while others are still figuring out what they will need. You should be able to get on the road and out or the impact zone in your vehicle. If you are caught un-awares you can don your packs and start walking. This is not recreational hiking with a light pack - this is evacuation with a cargo pack - you won't be in the woods but on the roads. A good suggestion in this sort of situation would be a wheeled hand cart that you could drag / push down the road. If there is significant social disruption AKA riots and you can't safely bug-in then drop as much gear as you can and hit the road extremely light. In this situation stealth and speed are mandatory. In all of these situations the overlap between preparedness and hiking gear is coincidental. <br><br>From the perspective of backpacking and other sports the requirements vary. I would think that if you enter the woods well prepared for a multi-day hike then you have properly prepared for whatever contingencies you might encounter in that environment. Of course this means that by the standards proposed by most other hikers you will be overloaded. Here more than anywhere else you make the trade between gear - knowledge/skill - weight. knowing how to make a friction fire allows you to lighten up you pack. knowing how to hunt and gather allows you to lighten your pack. knowing how to cook over an open fire allows you to lighten you pack. OTH having an MSR whisper-light, espresso star and maker, MSR titan fuel bottles and cookset adds about 3 lbs but makes dinner and camp much more comfortable. In decent weather a mesh hammock and fleece blanket can provide shelter for less than a pound but don't get caught in a rain. Add another pound for tarp and your good at 2 pounds for summer - go into the mountains or out in winter and you will carry 7 pounds of shelter and like it. - or you could get good at debris huts and snow shelters....<br><br>If you cook over open friction started fire hunted and gathered food and sleep in debris huts in your clothes and like that for comfort then I would bet you could be fine with nothing more than a butt-pack and holster.<br><br>If you skill level and comfort requirements are similar to mine you will have a difficult time keeping your pack capacity below 2500 ci and weight below 45 pounds. YMMV