The Rule of Three’s is a helpful guide to prioritizing your plan in a survival situation, by spelling out the average time a person can survive without basic needs.

According to the rule of three’s you can survive:

3 weeks without food

3 days without water

3 hours without shelter

3 minutes without air. 

When teaching survival courses, I add one final category: 3 seconds without a POSITIVE ATTITUDE.It is generally met with a chuckle or two when I explain this, but DO NOT underestimate the importance of this category. It is the one, above all others, that gives you the best chance of staying alive. Just as one can have all the kit in the world, and still be doomed by not knowing what to do with it, one can have every odd in their favor, yet without the will to push on and live; you are as good as finished.

Knowing the Rule of Three’s will help you to structure and schedule what you really need to do first. For example, I often ask students to list their priorities in a survival situation.

More often than not food will be near or at the top of the list, with things like shelter near the bottom.

If one were to follow that mindset in a survival situation, they could unwittingly burn countless energy and time searching for food, something that they could live without for weeks, and never take the time to build a life saving shelter that would get them safely through the night.

By knowing your Rule of Three’s, you can assess your situation, and develop a concise plan of action in accordance with your immediate needs for survival.

It is important to remember that, like anything, the Rule of Three’s is situational.

For example, in a temperate forest in summer, one could potentially last far longer than three hours without shelter. Yet in a winter clime, one could have significantly less than three hours to establish shelter, just as three days without water could suddenly shorten, were one lost in a hot, arid setting such as a desert.