The named packing rules, explained

#Why this page exists

Search for any of "the 20 rule," "the 3-3-3 rule," or "the 7 C's of camping" and you will get a confident-sounding answer. Search for where the rule came from and, for most of them, you will get nothing. This page separates the two questions: 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. Every one below is a way to avoid over-thinking a pack, not a substitute for 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 capping 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 single named originator. Neither claim is backed by a citable primary source we could locate, and outdoor writers who have looked for one report the same gap.

What the number is actually worth: treat 20% as a ceiling, not a target. More recent load-carriage research finds injury risk rising well before 20%, and most hikers report feeling best closer to 15%. Fitness, trip length, and terrain change the honest number more than the percentage does — which is also why "20%" survives as a rule of thumb rather than a measurement: it is a single number standing 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, and only one of them 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, echoed directly by the U.S. National Park Service, and it protects water sources and wildlife access — not your pack weight.

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

#The 3-3-3 rule

The claim, and it has at least two incompatible versions: one version is a clothing capsule — three base layers, three mid layers, three outer/shell pieces, covering a wide temperature range on a short trip. A second, unrelated version applies to trip planning generally: three core categories (shelter, food, clothing) plus three backup essentials (light, first aid, fire).

Where it comes from: no traceable origin for either version. Both are travel- and outdoor-blog conventions, not the product of a research body or an outfitting organization. Treat "3-3-3" as shorthand for "keep your layering system small and legible," not as a specific inventory to hit exactly.

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

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

Where it comes from: general travel-packing content, with no traceable single origin. It is a mnemonic for building a small wardrobe that mixes and matches, not a camping-specific standard.

#The 7 C's of camping

The claim — and this is the rule with the widest disagreement: the more established version is an ethics checklist (care, caution, courtesy, cleanliness, cooperation, conservation, common sense), aimed at behavior, not gear. A second, gear-focused version swaps in categories like cover, cooking, comfort, and clothing. The two answer different questions and neither is "correct" — they are two mnemonics that happen to share a letter and a number.

Where it comes from: no single traceable origin for either version. Both circulate as camping-club and outdoor-blog conventions.

#The takeaway

None of these rules is wrong to use as a mental shortcut before you pack. None of them is a standard anyone enforces, and only the 200-foot distance rule traces to a documented source you can actually check. Use the checklist above as a category-by-category sanity pass — it will catch a forgotten item faster than reciting a mnemonic will.

Add these to a list you can check off. The items above go straight into a trial gear list you can build and keep without creating an account — useful whether you are checking your own pack against a rule of thumb or just making sure nothing is missing.