How do you guys rule quick takedowns in your games, for example if your acolytes are infiltrating an enemy camp and want to quietly take out a sentry, how do you it in a way that is satisfying and achieves their goals if they roll well?
The reason I ask is, if an acolyte sneaks into point blank range, places a silenced stub revolver on the back of the sentry's head and pulls the trigger, or perhaps slips a blade into their kidneys, that sentry should be dead. RAW that isn't going to happen.
The way I'm thinking of making it happen is that they still roll to hit with all the associated modifiers (perhaps after succeeding and opposed stealth/awareness test to get into position) and skip the damage phase (falling back on the rule that you don't need to roll for things that the GM deems automatically passes). My problem with this is that it starts to become a bit more complicated once you factor in armour and different melee weapon types (although the GM can always decide on the fly if x weapon vs y armour qualifies for the insta-kill).
Your thoughts are appreciated