I don't know if other genre writers play the game, but science-fiction writers sure do: What if...and then?
Theodore Sturgeon said that the key to being a good writer was to ask the question "What if?" And the key to being a great writer was to ask the next question.
In science fiction, it works like this: Gun control is a hot issue right now. So let's ask some questions about gun control. What if...everyone was required to pack a weapon from the age of ten upward?
You could get a story out of that. But then ask the next question, which could go in infinite directions: What if mass murder became the norm and no one even noticed it? What if one kid absolutely refused to go armed? What if someone created a device that rendered all explosives inert, including those in cartridges?
You get more stories that way. Keep asking them and answering them in your head until you hit one that gives you an "ah-hah!" moment. There's your story: something no one else (to your knowledge, anyway) has considered in fiction.
It can work in all other forms of fiction as well. What if orphaned Oliver Twist breaks free of the workhouse and falls in with thieves? And what if, unknown to him, he is heir to a fortune?
What if a woman asks a detective to help her out of a jam on the very day after the detective's partner has been killed? And what if every word that comes out of the woman's mouth is a lie? And what if she is seeking a solid-gold statuette of a falcon....?
Sturgeon was right. You can get a whole lot of food for thought and a whole lot of mileage out of simply asking the next question.