Q: What monster would be hardest for our contemporary civilization to defeat?
A: A single wight could defeat all the armies of Earth at this time and enslave the planet. The wight is only able to be hit by plus one weapons and in our universe there is no magic. Therefore nobody could do any damage to the wight, even with a hydrogen bomb. Every time the wight claimed a victim it would become a half-energy wight under the control of the original monster. By a geometric progression soon the world would become nothing but wights.
Q: How do you know there are no plus one weapons in our world?
A: I’m a scientist and do not believe in magic.
Q: But if there were a wight there would have to be magic wouldn’t there?
A: I was considering the counterfactual — what if there were a single wight.
Q: Yeah but if you consider a counterfactual you have to consider a possible earth in which the counterfactual is actual. In the closest universe in which there was a wight, magic would be true, and thus, there would be other magical means of defeating the wight.
A: We are talking about a game. In the game you asked me to imagine a wight. Not to imagine a magical world with a wight, but our world, but with a wight.
Q: But to play a game means to interact in a meaningful way with the universe of which the game is a part.
A: Games are different from reality. You are dumb.
Q: How do you know I am dumb?
A: I checked your intelligence score. It’s 11. Mine is 16.
Q: Hey, couldn’t we just defeat the wight with a silver weapon?
A: Fine. A spectre.