A Stock Character
is a character who is instantly recognizable to us from other stories; the gruff grandpa, the snooty cheerleader, the bratty younger sibling. You can sum up their role in the story in a sentence or less and people will know exactly what you're talking about. Such characters are frequently one-dimensional in nature
. Sometimes that's okay
. Sometimes that opens the door to Playing With Tropes
as well. Sometimes two or more character types get combined as well.
Any Main Character
will likely have any number of these tropes depending on the story.
A stock character can be an Archetype
, an example of Characters as Device
, or just very recognizable (Mary Sue