1. Reasonable: The use of force must be reasonable, meaning that it is justifiable based on the circumstances known to the person using force at the time. It involves assessing the threat, considering available alternatives, and making decisions that a reasonable person in a similar situation would make. The actions taken should be logical, sensible, and in line with accepted professional standards and training.

2. Necessary: Force should only be used when it is necessary to achieve a legitimate objective, such as protecting oneself, others, or property from harm. This means that all non-physical and de-escalation techniques should be attempted and exhausted before resorting to the use of force. It also implies that the force used is the minimum required to achieve the intended outcome.

3. Proportionate: The level of force used should be proportionate to the threat faced. It means that the amount of force applied should not exceed what is reasonably required to address the immediate situation. The degree of force employed should be based on the level of resistance or threat posed by the individual, taking into account factors such as the individual’s size, strength, behavior, and the level of risk to others.

Determining the reasonableness, necessity, and proportionality of force is a subjective judgment based on the facts and circumstances known at the time of the incident. It is important for individuals who may need to use force, such as security professionals or law enforcement officers, to receive appropriate training that includes instruction on assessing and applying force within these principles. These standards help ensure that the use of force is justifiable, controlled, and carried out in a manner that respects human rights and safety.