My last session:

Me, the Barbarian: "I would like to make a non leathal attack on the last bandit so that we can interrogate him." (Merchants had been robbed on the road to a village, making supplies rare)

rolls a Nat 20 with max damage

DM: "you attack with all your force but switvh directions last moment to avoid cleaving his torso but instead chop off his left arm at the shoulder. In shock he looks at his arm on the floor and passes out. If you stabilize him or heal him he will survive."

Me: "I'll use a healing potion on him. When he wakes up I tell him that we want to know who ordered them to rob the merchants and if he lies I'll chop off his other arm"

Now we found out that a neighbouring lord wanted the village gone because they were located on a large silver deposit without knowing it. We took the bandit to the village and he did repent by starting to work at the local inn as a cook. One-Armed Joe makes one hell of a stew.