Let’s say you were running a science fantasy game and introduced this item:
Bolt Thrower: Lets any character use the Ranger “Blot Out the Sun” move to do damage +1. On a 7-9, the weapon jams after firing and can’t be used again until repaired. On a 6-, the weapon backfires and the wielder takes 2x damage +1.
Now let’s say you’ve got orcs wielding these things – how do you handle the monster’s potential for backfire since the monster doesn’t roll to attack?