Two is One and One is None: What Does the Saying Mean?

There’s no way to predict what will happen at any given moment. When you’re out in the elements, that unpredictability can be potentially life-threatening. As Murphy’s Law tells us: “Anything that can go wrong will go wrong.”

But there is another lesser-known saying out there that may just be the survivalist answer to this eventuality.

“Two is one and one is none” is a way of stressing the importance of a good backup plan. It illustrates that having only one of something is the same as having none while having two of something is just like carrying one. 

Though it may seem like a ridiculously simple concept, there are still some things you want to keep in mind when prepping your backup plan. Let’s take a closer look at this saying and how you can effectively put it to use in your survival prepping.

What Does “Two Is One and One Is None” Mean?

There’s some discussion about where the quote “two is one and one is none” originated. Navy Seals, Marines, and Army Rangers all tend to claim that it started with them. But one thing everyone agrees on is that this incredibly useful way of planning strategy began with the military.

The basic idea behind the quote is that you should always have a backup in place for your most important plans and gear before you start off anywhere.

Redundancy is often viewed as a bad thing. It’s used to refer to something you have to do twice or duplicate things you have around your house. However, when you look at it through the right lens, redundancy can be what saves a bad situation from turning worse.

For example, let’s pretend you’re miles from civilization, it’s getting dark, and suddenly your flashlight fails. If you only have one source of light on you, that’s just as good as not having one at all. Now you’re traveling in the dark, hoping for the best.

But if you have an extra flashlight, extra batteries, or another way of lighting the path ahead, you’re good to go!

How to Use Redundancy to Your Advantage

This concept is all about being prepared for the worst-case scenario, but it’s not as simple as bringing two of everything. In fact, properly employing “two is one and one is none” takes a bit more thought about what you need to survive and what you would do if those things failed you.

Here are a few things to keep in mind while you’re making your backup plans.

Duplicate Capability, Not Exact Gear

One of the easiest examples to look at when it comes to redundancy is fire starters. By carrying multiple fire starters you can greatly improve your chances of creating a successful fire.

Lighters are a common form of firestarter. They’re easy to get ahold of, compact to carry, and easy to use. Sure, you can throw an entire box of butane lighters in your pack and call it a day. If one goes out, you can always use another one. Right?

That’s where you need to look at redundancy from another angle.

Before you start tossing things in your pack, try to imagine the ways those things could fail and then find ways to cover those possibilities.

Lighters don’t work well in cold weather or for lighting wet objects. They can also run out of fuel or just refuse to light altogether. If you have only lighters in your pack, none of them are going to work for you under these conditions.

But if you’ve already thought about this and packed a few different types of fire starters, such as Ferro rods, matches, or flint, then you know you have another way to start a fire and keep warm even if your main lighter up and quits on you.

Use this thought process for every backup you bring with you. Make sure it covers the same capability as your original item without the exact same pitfalls. That way you have something for any conditions.

How to Carry Backup Items

Almost as important as what you carry is how you carry it.

Putting every single spare pair of glasses you bring with you in the exact same pocket of your pack isn’t going to do you much good if you lose your pack. If your things get dropped and land in just the right way to break your spare glasses, you don’t have your backup anymore.

Disperse your backup gear in different parts of your pack and on your person.

Prepare for any eventuality. Invest in waterproof and drop-proof cases and bags for important items. Pull a Teddy Roosevelt and keep a pair of spare glasses in your hat!

The important thing is that if something were to happen to your bag or even just one part of your bag, you still have options available to you. It’s not a lot of good carrying more than one of something if all of that extra effort is ruined all at once.

What Do You Need to Bring Extras Of?

Implementing “two is one and one is none” is a deeply personal practice. There’s never going to be total agreement on what items everyone should bring extras of because everyone’s needs are totally unique.

While you’re creating a game plan, make a list of the things you absolutely know you need in your pack. These non-negotiable items are what you should be getting two or three or even more of before you head out on the trail.

That being said, there are a few categories that most people agree on in the case of redundancy:

  • Knife / Multi-tool
  • Firestarter
  • Light source
  • Navigation (map, compass)
  • Signaling for help
  • First aid
  • Water filtration

The most important thing is that your basic needs are being met. Even if your favorite knife breaks, you still have a way to cut cords and firewood. If your bandages get wet, you have backups in the event you get hurt.

With redundancy on your side, you’ll be totally prepared when anything that can go wrong goes wrong.