Charles W. Bryant,
HOW STUFF WORKS, This essential tool will always surprise you with how many ways it can be used, including securing equipment, making traps and shelter construction. There are many types of rope and cordage out there, but most experts agree that for a lighter load and superior versatility the best all-around cordage is the military-brand 550 parachute cord, which gets its name from its 550-pound test strength. This legendary cordage is woven from seven strands of white nylon that can also be unraveled and used as heavy thread or string, making it an ideal multipurpose survival tool. 550 cord is too slender to be used as climbing rope, but there's no reason you can't include some dry-treated, non-stretch nylon rope in your survival kit as long as you're willing to accept a bulkier load. While we're in this category, do yourself a favor -- pack a spool of snare wire and a small reel of fishing line with a hook. And if you don't know how to tie a few basic knots, you're almost better off leaving the rope at home!