At first, I didn't know what "nova" meant, but I've seen it enough in context to infer that it means "doing a ton of damage in a short period of time." Later I discovered that the term isn't as common as I first thought. It must just be in the communities I'm involved with (D&D). Essentially a nova-based PC is one that can expend a large amount of a limited resource all at once in an attempt to do massive amounts of damage. This would commonly be used when building an assassin type character.
How was this term coined? How was it popularized?
I had guessed that the term was just metaphorically referring to a supernova, but it seemed to be used frequently enough that it may have a specific origin.
Best Answer
The reason that this astronomical term is used to describe a particular kind of attack comes from the "nova flame" or "nova blast" of the Fantastic Four's Johnny Storm ("The Human Torch"). This was a power that could do astounding amounts of damage in a single burst, but leave the hero spent and powerless for a time. The term was picked up and used in Champions, and then spread from superhero RPGs to other forms of gaming.