Many games draw moral lines in bold colors, where the real world is not so easy to categorize. Suppose that the player characters are faced with an overwhelming foe? Even unsavory allies such as orcish barbarians may be better than no allies at all. More disturbing, these allies may be honestly friendly to the PCs when all is done, overcoming barriers of race and religion. Will the PCs remain friendly with the bloodthirsty humanoid tribesmen when their mutual foes are defeated? Some would expect the tribes to betray them, but after the characters have honestly won their respect, even orcs may not be all bad.
A girl living in an isolated hamlet is cursed: So beautiful and sweet-natured that no man can resist loving her, but she has never met the man she could love in return.
A powerful wizard that the PCs encounter is completely silent. He does not speak and cannot be heard as he moves. Even his spells are silent, but his magic is just as potent.
He has a tendency to summon invisible chairs, place foes in invisible boxes of force, and other "mime tricks".
In a long-lost age, a party of adventurers are frozen into stone by the stare of some gorgon-like creature. An unscrupulous rogue, coming across the frozen party several centuries later, decides to haul off two of the statues to decorate his den. Upon his death, an artisan friend of his claims a statue and sells it to a rich merchant, passing it off as his own work. Years later, the merchant gilds the statue in bronze and re-sells it at a much higher price. After passing through the art markets for many decades, the statue ends up in the hallways of a mage academy. Imagine the chaos and confusion when a young mage's spell happens to break the curse of stone, returning the adventurer to life several centuries after his petrification! Is he interrogated by historians? Driven mad by the change of times? Or does he set off on a quest to find and liberate his other frozen party-members?