Manbearcat
Legend
<snip> but honestly, the real secret is PLOT and ACTION. Its fine if the guy that goes first doesn't have a CHA skill, he should be able to do something else, that's all.
This cuts to the core of 4e. But I'd scale PLOT back to just CONFLICT. That is what 4e's engine does; CONFLICT and ACTION (/adventure). One of the great tragedies of 4e's demise is how trivially easy it is to just improv a session out of whole cloth.
A few weeks ago, plans fell through on an evening so I introduced a few new people (along with a long time player) to TTRPG with a complete off the cuff session of 4e.
1) Players made 1st level characters (sans CB) with PHB1/2 using standard array.
2) We settled on play being centered around pretty straight-forward tropes; (a) a village with a horrible secret and (b) a haunted forest. We drew a quick map with the village, the forest, and then took turns putting an area of danger/discovery on the map.
3) The players picked 3 Themes/Backgrounds from NCS (generic-izing them a bit). Together, they came up with a quest for each T/B and wrote each on a separate flash card. I shuffled them and handed them out to the players.
This setup took about 40 minutes (with silliness and friendly jabs included). That left about 2 hours and change of gameplay. The village was was basically riffed off of 1770s pre-revolution Boston only the occupied peoples were quietly worshipers of this voracious thing in their well. The forest turned out to be haunted by malevolent elven spirits who died a century ago at the hands of an opposition clan who wanted to live peacefully with the first colonialists.
We had massive village-threatening fire that had to be put out (which turned out to be arson), a chase, an exorcism, the attempted talking down of a group of rioters against a terrified group of soldiers (lol Boston Massacre?), a witch hunt - all SCs - and a pair of combats.
CONFLICT and ACTION (/adventure). Off the cuff just using the PC build tools, monster math/tight encounter budgets, level 1 damage expressions/DCs, RC SC framework. Done. 4e is excellent at taking you through D&D's story (from levels 1-30). However, its streamlined nature and core design of closed-action-scene > transition scene > rinse/repeat (and everything integrated into that paradigm) with pushing play toward and then resolving the conflicts that the players have signaled they care about (through PC build choice and quests) makes fun free-form one-offs like the above an utter cinch.
It didn't, and still doesn't, get nearly the credit it deserves for this.