I am glad the LintKing reads the books. Because he's the one who answers the questions when I ask, "OK, what should we roll for this?"
Take, for example, the incident tonight.
Drythar, Beryl, Molivus, and Thorn have made it out of the ancient coliseum.
Between commentary (there's only two of us - you'd think we'd move faster than this... but discussion ranged from banana nut muffins, blue penguins who are actually god-emperors of the multiverse, mufflers of gold, and scarfing food) some fifteen minutes later our intrepid heroes manage to open the door.
A minute later, there's a whistle from behind them, and then one of the strange glass arrows (with obsidian "fletching") is fired above their heads and into the ancient cactus directly outside.
(They haven't observed, passively or otherwise, that this is actually not the first time for this to have happened.) (Or the skill of the archer - it should have slid right through, but...practice, after all.)
So, should they turn directly around they could have caught the gaze of the lurking medusa who's been playing with them for about half an hour of their "careful" trip through the hall of statues.
I want them to roll to fail the automatic reaction of trying to make out something in the gloom they left. I'd rather not deal with two more statues, not that I can really find any petrification rules. (It's probably something you can "self-heal," muttermutter. Did I mention I made my cleric/mage a warlock instead? It's seeming to fit better.)
What do they roll? And if they fail it, do they roll a saving throw?
"I should have stuck with THAC0," is like our theme song.
We went with a wisdom check and yes, saving throws. Which suck hard in 4e, but we're trying...really.