Rucksacks or rucsacs as they are sometimes spelt, are the single most important part of any backpack. This is because without a rucksack all the useful pieces of survival equipment that you accumulate would be unsupported and roll off of your back completely.

A rucksack is simply a bag with shoulder straps, larger versions also have hip supports, which take a lot of the pressure away from the back, but essentially they all have the same purpose, to carry a load on your back, thus leaving your hands free for other tasks, such as map reading, balancing or looking at your digital watch.

When buying a rucksack, three factors have to be considered.
Firstly, how much equipment is to be carried. There is no point in purchasing a 95 litre round the world trekking sack, if all you need to carry is a change of underwear and your lunch.

Secondly, if you are going to take absolutely everything you can possibly think of except, maybe, the kitchen sink, then you must be strong enough to carry it. Some long distance trekking needs months of physical training to prepare for. A good hip belt is vital on the bigger sacks, this will take a lot of pressure from your spine and save bundles of cash on chiropractors fees in later life.

Thirdly, good rucksacks cost lots of money, sometimes travelling on a shoestring can mean compromising on cost, but if you buy a cheap inferior pack, you can be risking broken straps, split seams and backache. Now if you lose this piece of equipment, where will you put everything else?

Of course, however, if buying a top notch rucksack means going without a sleeping bag then its probably better to keep warm.
See also: sleeping bags