“We’re going to head straight there, with haste!”

—My party

I tried running Descent into Avernus and my players ended up somehow turning a random encounter at a watchtower into an entire subcampaign of shadow of Mordor style attacking devil generals…

They got insulted by the head of the watchtower guard and decided to take it up the chain of command… I thought they’d leave it but after two levels they fought a devil general which led to Bel (they were on the other path). They couldn’t defeat Bel, so they decided to weaken him by killing his army (which lead to more demons entering Avernus)

Honestly it was pretty fun to dm, I was not prepared for that level of derailment, but rule of cool won out.

You can’t admit that! Gotta make it a place that’s so boring they won’t go there until you come up with the real idea