U see I only have the vanilla set and it somewhat luck's the simplicity and the role play ability of what I need so I use many home-brew rules and mechanics..let me give u and example of how I roll..I only use the stuff from the game so nothing else is needed except pen,paper AND SOME FANTASY!!!
I ask my players(victims) What kind of class u want to play???Anything just ask for it..
Solider?ninja?paladin?knight?druid?thieve?mage?necromancer?pyromancer?elf?dark elf?monk?cleric?undead?vampire?dwarf?dragon slayer?What??WHAT???
After that I ask them to tell me some of their backstory real fast and generaly..for example:"I'm a paladin traveling far to do justice for my god!!!"
-GREAT..pick a player card that u like for your persona!!!(I tell him as at the same time I look all the equipment cards,the treasure cards and skill cards to see what is relevant for a Paladin..)
I take all those cards that could be used by a paladin and sort them up real quick as starter equipment and one starting skill or two..(if the equipment is low power cards I give them two secondary skills,or the other way around)..U just need to make the mix have some flavor on it..You have a hero born in 5-10 minutes all geared up and ready for his adventure!!!
All the other cards are kept for treasure finding,leveling up and even for plot (legendary items or whatever..u get the point..the cards and the back story of the player create the adventure,or campaign.. whateveeeer)
U say a few words to your player.."u arrive at a small village(the market should have a few potions or something of interest to buy or sell maybe)..bla bla bla..where u find a tavern(let them pay for a drink,a bed or some info)..bla bla bla..and u set off to kill the Demon(think of the stats or character for the bad guy)..bla bla bla..who lives in the empty temple of..BLA BLAAAAA..ok???simple so far?
U can also have a small map of the area around the village where the story takes place..that could help u too..about where the battles will happen(some thieves with some easy stats and low equipment and their boss may have a skill) and how the place would look like..add rocks,water,branches,ruins,fire,webs,doors,stairs whatever..2 minutes most no more no less..hide some treasure on a question-mark and have them make a perception check to maybe find some,more,or all the treasure at that area,or to avoid a trap,or whatever u like man!!!don't forget..u write the story of a hero,have fun,throw them dilemmas,story,even a company hero maybe a low stat squire to help them ..kill the squire!!!FIGHT THE DEMON!!!