Is there a good way to introduce a monster’s passive qualities in the face of successful player dice rolls?
Let’s say I have a beasty that cannot be attacked in a certain way, e.g. it is impervious to magic. My group gets into a fight with this monster, the Wizard reacts first, and casts Magic Missile. He rolls a 12!
So do I then just say: “well, your spell was totally successful, it just doesn’t do any damage at all, sorry”? Seems a bit contrary to the spirit of the player’s excellent roll. (On a 6- or even a 7-9 it wouldn’t be a problem at all, of course.)