In assessing negligence, when is there a duty to act?

While many laws prevent you from acting in certain ways, there are generally few situations where the law requires you to act or do something.

Imagine if Bob was at the beach. Suddenly, Bob notices a child drowning in the surf. Bob grabs his binoculars, sits on his towel with a tub of popcorn, and watches the child slowly dip under the waves, never to be seen again. At no point did Bob try to help, or alert anyone, of the child's peril. Is Bob a monster? Yes. But did Bob do anything legally wrong? No. As cold as it may seem, people have no duty to be heroes. As far as the law is concerned, we are playing by Nature Documentary Rules, where we can sit back and watch the universe play out without ever having to get involved. But there are some exceptions.

One exception is if you choose to get involved, then you may have a duty to follow through. Imagine if Sam was at the beach with Bob and also saw the boy drowning. Sam quickly strips down to his swimsuit, runs to the water's edge, and dives in. When Sam gets about halfway to the drowning boy, he gets bored and is no longer interested in being a hero, so he stops and swims back to shore. The child drowns. Here, Sam would be liable. Why? Because there is a chance that someone else was going to genuinely attempt to save the boys life, however, when they saw Sam swimming towards the boy they figured the problem was solved.

In other words, where your actions dissuade others from acting, then you may have an obligation to act and follow-through on your act.

A second exception exists when you are the person who causes the danger to another. While there is generally no obligation to assist others in peril, that doesn't count if you put them in peril. For example, if Bob and Sam are hiking near a cliff, and Bob jumps out behind a bush to scare Sam as a prank causing Sam to slip off the edge and hang on for his life, Bob has a duty to help Sam. Not because Sam is hanging on to a cliff for his life, but because the reason he is hanging on to a cliff for his life is because Bob pranked him.

A third exception exists when a special relationship exists. While the law doesn't expect strangers to have duties to other strangers, it does expect some duty of care between those who have an existing relationship of care. A parent has a duty to try to help their child, an innkeeper has a duty to their guests, etc.

Finally, a fourth exception exists where an individual has the power to control the actions of another person who is an apparent risk to others. For example, if one of your employees gets into a verbal altercation with a customer that escalates to your employee jumping over the counter with his fists clenched, the law doesn't expect you to physically stop them from hurting the customer — but you need to at least order your employee to stop what they are doing and attempt to influence their actions.