How do I prep for each session? I’ve actually written about my prep habits multiple times in the past, and the basic answer is - it depends.
Sometimes it depends on the game I’m running. 4e takes me a fair amount of prep time, but nothing compared to running 3.x at similar levels took. OSR games tend to take less time, but that’s balanced out by the fact that I tend to do everything myself.
For 4e I’m running the WOTC adventures, so the prep time isn't necessarily difficult, but it can b time consuming. Mostly I just need to adjust the stats to deal with the fact that the game balance wasn’t quite right initially and my players are excellent character builders. I’ve also done a bit of tweaking of maps and a bit of monster/trap swapping to make things feel more cinematic.
In my 3.x days I had a lot of work to do, since I was running multiple groups at the same time. While I was using modules (mostly) I was also heavily modifying things as the games went on. Prep time for 3.x games was one of the reasons I latched so quickly onto the OSR once I discovered it. Being able to make adversaries for my players took forever, and most of it ended up not being used. Who cares what 1st levels spells the 20th level lich has? Is it going to show up in game? Probably not. Lessons learned.
As far as my old school games go, lots of the prep has been spent building my megadungeon. The times I’ve run Stonehell, there’s been very little prep. I just read the area I think (or know) the players are going to head into, and then I roll some dice. If they venture into a different area, I take 5, read, and back to the game.
Aside from direct prep, I also like to prep the area I’ll be gaming in. For my old 3.x games and my 4e, it means setting up the table, having the minis handy, making sure that distracting things are out of the way/out of sight, and that I’ve got my game music queued up and ready. Snacks and drinks were usually someone elses job when I DMed.
Online games are similar, I want to make sure I have my needed books, maps, etc. handy, along with a notebook, and again, something to drink. I don’t usually eat during my online games.
DMing is a thirsty business. Usually I go for water, since I mostly just need to keep my throat hydrated, but sometimes I’ll have a beer, then switch to water.
Post 8 in the 30 Day DMing Challenge.