The Rule of Threes – How to prioritise in a survival situation

The Rule of Threes is a guideline often used in survival training to prioritize essential needs in a critical survival situation. It outlines the basic timeframes within which a person can survive without specific resources.

Decision: STOP (Stop, think, observe and plan). Make a decision within 3 seconds. Do a rapid initial assessment of what has happened, where you are and what you need to do.

Air: You can survive only about 3 minutes without air. This priority addresses situations involving airway blockage (First Aid), the inability to breathe (under water) or toxic environments, especially where smoke or gases are involved. Immediate action must be taken to remedy the situation. If you manage to survive the first three minutes then chances are you’ll make it to the first three hours.

Shelter: Exposure to harsh conditions without adequate shelter can be fatal. You can survive approximately 3 hours without shelter in extreme environments, where protection from extreme heat (heat stroke) or cold (hypothermia) is crucial. If you manage to survive the first three hours then chances are you’ll make it to the first three days.

Water: Dehydration is a serious concern in survival scenarios. You can survive about 3 days without water, depending on the climate and your physical condition. Procuring and securing a drinkable water source is essential. Treating the water to ensure it does not make you sick is also essential. If you manage to survive the first three days then chances are you’ll make it to the first three weeks.

Food: While important, food is lower on the list of immediate survival priorities. You can survive approximately 3 weeks without food. In a survival situation, your focus should be on the procurement of air, shelter, and water before food. Once you have secured air, shelter and water you can then start foraging for food. Prioritise high calorie food where possible. The goal is to conserve energy. When we expend energy looking for food we need to ensure that the calorific reward from the food we eat exceeds the energy used to secure it in order to prevent an energy deficit. Food high in fat contains more calories than plant leaves as an example. If you manage to survive the first three weeks then chances are you’ll make it to the first three months.

Human connection (for mental health): In prolonged survival situations, being completely isolated or lacking interaction with other people can lead to psychological distress and mental health issues. Human beings are inherently social creatures, and lack of social contact for periods of longer than 3 months can affect mental and emotional well-being significantly. If you manage to survive the first three months then chances are you’ll make it to the first three years.

Habitual environment (community rebuilding: Over extended periods, the need to establish a stable community or adapt to a new environmental reality becomes critical. This involves forming a sustainable living situation that includes stable food sources, secure shelter, and a functioning societal structure to support life over years. This is about moving from mere survival to rebuilding and thriving in a new status quo and is achievable within the first 3 years. If you’ve managed to survive the first three years chances are you’ll be able to continue supporting yourself to survive as long as it takes to be rescued.

These extended applications of the Rule of Threes highlight the importance of psychological and societal needs alongside the basic physiological requirements for survival in long-term scenarios.

Understanding and applying this hierarchy can help manage decisions and actions effectively when faced with a survival situation, ensuring that the most critical needs are met first to increase the chance of survival.

The 5Cs of survival devised by David Canterbury

Survival expert Dave Canterbury has popularised a framework known as the '5 Cs of Survival’ which outlines the...

Fuelling your adventure – Basic nutrition for Outdoor Activities

Spending time outdoors can be hungry work, especially when doing something particular active like hiking, climbing,...

5 ways to light a fire – From friction to flame

Fire has played a central role in human evolution, profoundly influencing the trajectory of our development. The...

The Rule of Threes – How to prioritise in a survival situation

The Rule of Threes is a guideline often used in survival training to prioritize essential needs in a critical survival...

Survival Priorities – Core temperature control

Maintaining core body temperature is fundamental to survival in any environment. This delicate balance, often...

The 5 Ws of Shelter Site Selection – Choosing the best site

When it comes to survival, the choice of where to build your shelter can be as critical as finding water or food. The...

The 5 Ws of Survival – Understanding the Basics of Survival Skills

Survival situations can arise unexpectedly to anyone, anywhere, whether you are on a hiking trip, caught in a natural...

10 Poisonous Plants in the UK you should know

Learning to find food in the wild is thrilling, foraging for edible plants that can sustain and revitalise us if...