Genuine Question: does calling your characters OC's only really apply in a fandom context or is it one of those terms that spills out and non fandom creators also call them OC's? (im rly sorry if its an odd question but I don't know where to ask it)

All original characters made by you are ocs regardless if they have their own original universe or they exist in a fandom universe. So if you make a character in like... Baldur's Gate 3 or your own TF2 character that's a scout or something, they are still an oc