I've mentioned the Dwimmermount / ACKs campain we run before, and in both cases I mentioned the cleric Three Steps.

What follows is a perfect example of both how players can gloriously throw total monkey wrenches into a beautifully configured set piece, and how this is made possible by a rules structure that encourages players to tell the GM what they're actually going to do instead of what skills and proficiencies they're going to employ.

Last we heard, the party, which includes not only the requisite mage (alchemist) and a paladin carrying a sentient sword that keeps wanting to kill said mage, but a pet "corpse eater" - a carrion crawler with the serial numbers filed off - that Three Steps charmed, had acquired a lantern, a sign from the gods of Law.

Now, as a GM, I don't make a practice of telling the players everything about a magic object unless there's a reasonable way to find out via the appropriate research or easily assumed testing. The usual "It's not cursed, hey, this armor is tougher than usual, oh, and it's light too," routine. Most common items - armor, weapons, are fairly straightforward. Rings and wands and potions get more complicated.

So it turns out the magic lantern had several spare lenses for a reason.

After dealing with several groups of ghouls, they come across an odd room with two better-preserved undead acting all too friendly in a chipper british-upper-class kind of way. They were all set to make an offer to guide the party to a couple locations of interest in exchange for a few guests for dinner selected out of whatever or whoever they ran into.

The party would have disagreed. OK, maybe not the assassin. Or the alchemist.

It became moot when Three Steps held up his lantern and decided that he was going to "turn" them with the holy light of his lantern. And so, to everyone's shock, as the beam of the lantern fell upon the ghasts, they came apart in a pile of drifting ash, their clothes falling to the floor. Unbeknownst to Three Steps, the lantern, other than never going out or requiring refuelling, could also be used to turn undead as a very high level cleric, at the cost of burning out a lens.

ACKs, and games that lean more on people telling the GM what's going on than rolling against a long list of skills and proficiencies, allow players to make the intuitive leaps like this based on what you describe. Because, with TS being a cleric, and the lantern being obviously a gift from the gods, of course it would be impressive to turn them by shining a holy light upon them.