In simple terms, plot armor is when a character survives a dangerous situation or escapes death due to seemingly impossible circumstances. It is a term used to describe a character’s ability to survive in situations where they should have perished. For example, a character might escape a burning building without a scratch or make it out of an all-out gunfight not hit once.
The use of plot armor is often criticized by readers as it can feel like a cheap way to keep a character alive. When used excessively, it can undermine the tension and stakes of the story and make it feel less believable. However, there are times when plot armor is necessary, keeping the relevant characters alive so that the story can happen.