The named packing rules, explained

Why this page exists#

Search for "the 20% rule," "the 3-3-3 rule," or "the 7 C's of camping" and you will get a confident answer. Search for where the rule came from and, for most of them, you will get nothing. This page keeps the two questions apart. What does each rule claim? And can that claim be traced to anyone in particular?

A rule of thumb is a starting point, not a specification. Each one below saves you from over-thinking a pack. None of them replaces checking the pack itself.

The 20% rule (pack weight vs. body weight)#

The claim: a loaded backpack should weigh no more than about 20% of your body weight. A 70 kg (154 lb) hiker would cap their pack near 14 kg (31 lb).

Where it comes from: sources disagree, and the disagreement is informative. Some trace it to mid-20th-century military load-carriage research. Others treat it as an undocumented rule of thumb that has circulated in scouting and outdoor manuals for decades with no named originator. We could not locate a citable primary source for either claim, and outdoor writers who have looked for one report the same gap.

What the number is worth: treat 20% as a ceiling, not a target. One recent peer-reviewed study of adult long-distance hikers (mean age 37, on the Camino de Santiago) found plantar pressure measurably worsening once load passed roughly 10% of body weight, well under the 20% figure. It is a single study and not a confirmed consensus. Fitness, trip length, and terrain change the honest number more than any percentage does. That is why "20%" survives as a rule of thumb and never became a measurement: one number stands in for several variables that do not compress into one.

The 200 rule — and the real 200-foot rule underneath it#

Two different "200" claims circulate under similar-sounding names. Only one has a documented source.

The genuine one: camp, cook, wash, and dig catholes at least 200 feet (about 70 adult steps, roughly 60 m) from water sources, trails, and other campsites. This is Leave No Trace guidance, repeated directly by the U.S. National Park Service. It protects water sources and wildlife access. It has nothing to do with pack weight.

The other "200 rule" is occasionally used for a gear budget and has no comparable documented source. Where the two get confused, defer to the Leave No Trace version. A land-management authority stands behind it.

The 3-3-3 rule#

The claim comes in at least two incompatible versions. One is a clothing capsule: three base layers, three mid layers, and three outer or shell pieces, covering a wide temperature range on a short trip. The other is unrelated and applies to trip planning in general: three core categories (shelter, food, clothing) plus three backup essentials (light, first aid, fire).

Where it comes from: neither version has a traceable origin. Both are travel and outdoor blog conventions, with no research body or outfitter behind them. Read "3-3-3" as shorthand for keeping your layering system small and legible. It is not a specific inventory to hit exactly.

The 5-4-3-2-1 rule#

The claim: a capsule-wardrobe formula of five tops, four bottoms, three pairs of shoes, two outer pieces, and one accessory. It was built for general travel, and some outdoor writers have adapted it for camping trips.

Where it comes from: general travel-packing content, with no traceable single origin. It is a mnemonic for a small wardrobe that mixes and matches. It was never a camping standard.

The 7 C's of camping#

The claim: this rule has the widest disagreement of the lot. The more established version is an ethics checklist (care, caution, courtesy, cleanliness, cooperation, conservation, common sense) aimed at behavior rather than gear. A second version is gear-focused and swaps in categories like cover, cooking, comfort, and clothing. They answer different questions, and neither is the correct one. They are two mnemonics that happen to share a letter and a number.

Where it comes from: neither version has a single traceable origin. Both circulate as camping-club and outdoor-blog conventions.

The takeaway#

Any of these rules works as a mental shortcut before you pack. No one enforces them, and only the 200-foot distance rule traces to a documented source you can check. The checklist above works as a category-by-category sanity pass, and it will catch a forgotten item faster than reciting a mnemonic.

Add these to a list you can check off. The items above go straight into a trial gear list that you can build and keep without creating an account. Use it to check your own pack against a rule of thumb, or just to make sure nothing is missing.