Rule of 3 – Survival

alone in the woods

What is the Rule of 3’s

What is the Rule of 3 as it relates to survival? The Survival Rule of 3’s is a philosophy or guiding principle that states as humans we can survive:

  • 3 minutes without oxygen
  • 3 hours without shelter
  • 3 days without water
  • 3 weeks without food

The Rule of 3 also establishes an order of importance in regards to how we should address certain things in a survival situation.

Where did these numbers come from? I have no idea and some limited research did not provide any satisfactory explanations. However, the Rule of 3 is widely accepted (dangerous precedent, I know) among folks from all cross-sections of society. With that being said, I feel like it deserves further discussion.

Rule of 3’s

3 minutes without air

Three minutes without oxygen seems like a no-brainer. I think everyone can agree that the air we breath is important and it is vital to our survival. It may seem like such common knowledge no one gives it any thought. However, think about the limited amount of time we have (3 minutes) to mitigate any issues related to a lack of air.

Three minutes is not a lot of time to make critical, lifesaving decisions oftentimes in the middle of a stress-induced situation. Now, you may be thinking, “what would cause me to be without air for 3 minutes”? A few examples may include:

  • Asthma
  • Severe allergic reactions like to something like a bee sting
  • Strangulation
  • Choking
  • Drowning
  • Suffocation
  • Collapsed lung
  • Inhaling toxic fumes
  • Heart Failure

Being able to respond to these types of things in a timely manner in and outside of the home is paramount.

Avalanches are a good example of Mother Nature being able to deprive you of air. Oftentimes, being caught in an avalanche creates a scenario where your body experiences a great deal of trauma only to be followed up by a situation where you have limited oxygen to breathe. Sometimes the weight of the snow alone is enough to squeeze the air out of you. Time is critical in order to survive these situations.

3 hours without shelter

Three hours without shelter seems like a short amount of time, but keep in mind, we are not talking about a picture-perfect day with a temperature of 72 degrees. Exposure to the elements is serious and is something that can sneak up on you before you know.

Extreme heat or extreme cold can get you fast. Add water to the mix and you are in a real jam. Even something like humidity, which may seem trivial, has a huge impact on the temperature range in which your body can maintain its core temperature.

You’ve heard terms like hypothermia, hyperthermia, heatstroke, heat exhaustion, etc., but for most Americans, these are not things we think about on a daily basis. During the course of a normal day, our level of risk related to these issues is typically low. Due to this, we become complacent. This creates a scenario where we do not respond, or don’t know how to respond appropriately and that’s when bad things happen.

There are also serious implications of weather we would consider to be somewhat moderate. Combine a cool temperature with moisture and wind and you have a recipe for disaster if you’re not prepared. Outdoor activities increase the likelihood of risk related to these conditions.

Moderate temperatures cause folks to go out unprepared for slight weather changes. Being able to have shelter is paramount. Simply being about to get out of the rain or get out of the wind can be a lifesaver. Having the knowledge, skills, abilities, and tools to acquire shelter is key.

Being inside the comfort of your own home eliminates almost all of these risks. However, what happens when the power goes out and you have lost your only source of heat. Check out our article on How to Stay Warm Without Power for more information.

3 days without water

polluted water source

Okay, so now you are good to go with shelter and it’s time to think about water. Dehydration is a real concern and it sneaks up on you before you know. Mild temperatures perpetuate this problem and it may set in before we know it.

Do you have the means to acquire “safe” drinking water in a survival situation? I say safe because you may have access to water, but it may not be safe to drink. One of the worst things that can happen is to drink contaminated water that induces vomiting or diarrhea when you are already dehydrated.

You need to be able to collect and purify enough water to sustain yourself in the environment and conditions you are in. Finding a water source is only part of the equation. Make sure you have the tools and knowledge to make that water safe to drink.

Having water storage at home is often overlooked because it is so readily available. However, there are some easy solutions to make sure you have enough water to by if the situation arises.

3 weeks without food

Three weeks without food seems like a long time, especially when I am ready for lunch by 11 o’clock every day. The effects of starvation will hit much sooner than the 3-week mark and you will know it. Much like water, having the skills to acquire safe food to eat is paramount.

Maybe you carry some provisions with you and they help you get by for a short time. What happens when those run out? Do you have the knowledge, skills, tools, and ability to harvest or gather food? Some foods have to be cooked prior to safe consumption, do you have the means to carry out that task?

Do you know how and what you can forage? Are you familiar with the plants, bugs, and insects that are edible and readily available in the area you are in? These are all things to think about prior to having the need to utilize them.

What about food storage at home? Do you have enough provisions to last 3 weeks? If not, you should start working towards a 30-day supply of food for you and your family. I little forethought goes a long way.

The good thing is with a little preparation you can help mitigate a lot of these scenarios. There are a lot of options out there to help you with your food preps.


Taking all this into consideration, I think we can all agree the Rule of 3 is more of a suggestion than a hard and fast rule. You’re not going to find any research to back up the claim that these numbers are universal and set in stone. There are too many variables and folks are too diverse for this to be true.

However, you will probably be able to find some sort of consensus in regards to the order of importance established by this “Rule”. But, even with that, there are too many variables that have an influence on the importance of what you should do and in what order.

My opinion is you need to be able to address all of these issues and be proficient in doing so. Having this proficiency will give you peace of mind and will allow you to take action if and when there is a need. This confidence allows you to go out and live life the way you were meant to.

What are your thoughts on the Rule of 3 for survival? Valid or not?


With over 17 years of federal law enforcement, training, and physical security experience, Cody focuses his time nowadays on both consulting and training. He regularly advises individuals, groups, multinational corporations, schools, houses of worship, and NGOs on security threats while conducting customized training as needed.

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