Related:
* Mercenary protagonist

Common in D&D and other games based on old P&P style RPGs where a "group of adventurers" do stuff, usually saving the world or a small part of it from certain doom.

Unlike mercenaries, adventurers usually choose the tasks for the sake of challenge, difficulty and personal reasons rather than the rewards garnered from it. Mercenaries also do not generally function as explorers and may take prolonged jobs that aren't particularly exciting or challenging. Still, there's significant overlap with the two.