Don't do too much, or you will waste time and efforts

I just plan out the world and where the NPCs are, and what their goals are. I don't really plan out what is going to happen with the story. I just let the players decide that, and have NPCs react appropriately to them when necessary.

Still things to prep. Encounters, maps, forces, terrain, ecosystem, descriptions, etc
- Yeah, things that, so long as they don't teleport somewhere for literally no god damn reason, will only change in response to something they do. If you plan for there to be a bandit camp in the, but they avoid it and set fire to the forest somehow, now forest bandits flee into the plains and set up camp again, interact with something there, or disband.
- :laughs in random table generation:
  
  I haven't actually prepped a session in ages. I learned The Keep on the Borderlands well enough, and use the encounter generation rules from the Rules Cyclopedia for everything else.
  
  I procedurally generate everything while we play. Which makes it a game for me, too - I get to interpret the results of the rolls in whatever way seems most appropriate and fun at the moment. And, in the end, it doesn't really slow anything down compared to 'normal' DMing, where I'd often have to cross-check notes, the adventure, etc to determine how the PC's actions play out.
- Encounters, easy. You were going to prepare those anyway.
  Maps, not as easy but there's resources online in a pinch.
  Forces... What do you mean by that?
  Terrain... That's just maps again, right?
  Ecosystem... Yeah, you're definitely over-preparing at this point.
  Descriptions... You shouldn't have been prepping this anyway. If you know what the thing looks like, you can describe it yourself during the game.

Or you can be like my boy who barely plans the next room

Am I your boy?
- yes, yes you are.

You know the famous quote?

Plans are worthless. Planning is everything.

Me: Planning 1 session in advance.

My players: Getting through 1/3 of what I expected and planned for.

Honestly kind of a godsend when that happens.
- Thats why I never stop my players from roleplaying. It saves on preps

I think the player types is important.

I've had players who will engage with stuff and make good things happen, and then I don't need to play very much. They'll see the awkward tavernkeeper and the village blacksmith and run cheering into ROM COM TIME. Can't really plan for that.

But I've also had players who are just wallflowers. They don't take initiative. They don't push for their own goals. They're timid and easily discouraged. "The tavern keeper doesn't want to give you the staff. It was his grandfather's, he says, and he doesn't want to hand it out to just anyway." "Uhh.. uh.. ok.. i don't know what to do. Can I charm person him?" "You can, but that's an escalation and people will be mad if they find out." "Oh nevermind I don't know what to do."

Meanwhile the other party got the staff by getting him and the blacksmith to finally go out on a date, and now they're all on great terms.

The timid party needs more planning (but still only a session or two in advance) because otherwise they're going to just stall out and get frustrated.

Maybe one day I'll have a group that's consistently engaged, thinks about the game between sessions, and knows the rules of the game reasonably well.

What is this word planning?

It's that thing you do in the shower the night before the session and forget to write down "but it'll be fine" and then you forgot half of it and only remember the dumb voice you gave the shop keeper. That, plus those notes you wrote down and you're sure you knew what you had in mind but now you're not sure what "damp lich" was supposed to mean.

I always over plan things. I'll plan encounters appropriate to level. I'll plan NPCs. I'll plan dungeon themes. But I won't plan a dungeon themed encounter unless I know they're heading into that dungeon because it's where we ended the last session.

To put it another way: I never plan so specifically that a thing can't be moved to another place unless I'm positive it's coming next.

Enlightened DMing is to simply set up all the pieces of the BBEG's plan on the world stage in your head or documents, and throw the players at it. Obviously, ensure that the plan is something the players have enough tools and resources to overcome, and prepare for what their decisions will likely guide them towards in the next session, but...

Any old video game can run you through a story. Few video games give players choices. And no video game can be truly derailed.

Understanding that getting derailed is arguably the entire point of DnD, is DM Ascension.

Getting derailed is easy. Making it fun for everyone DM include is the challenge. That is both a skill, luck, and mental energy that not everyone can or want to put in sometimes.

But I am not agreeing with the point of dnd. The point is the exact same as videogames, other ttrpg games, other TT games period. Having fun. Its really as simple as that. Which is why everyone should aim to do something they have fun with.

Just saying thought. If derailing the DM is the fun of a player, it sounds more like belonging to a horror story.
- Yeah, there's a fine line here. The DM improvising something whimsical and funny on the spot can be enjoyable to everyone, but if the party is going out of their way to do their absolute best to derail and force DM to waste any and all prepared material they're just dicks. The DM is still a player in the game doing it have fun too and doesn't owe you a campaign that bends to all whims of the party without restraint.
  
  Also, a good lesson for GMs is to try and write any prepared material in a way that allows it to later be reused if players manage to miss it. Just because the party didn't investigate that one cave with a goblin ambush in it doesn't mean they can't run into a goblin ambush later down the line somewhere entirely different.

What is "plan?"

Lol, my brother! I never have a plan. I built a bunch of encounters and quests on roll tables and have them as posts on the board in the Adventurer's Guild. They have tons of agency because I am exploring the world along with them.

The only way I'm planning 3 sessions in advance (beyond very broad strokes) is if the players have spent the entire session being unjustifiably paranoid of a random NPC who was never meant to be more than set dressing, rather than exploring what is presently prepared for them, hence what I actually meant to happen gets pushed back. So, all the time.

People complain about the mercer effect but I think his take on this is the best approach

Not all the balls to the walls set producing and stuff, but how he keeps important encounters ready in his back pocket should things turn back in that direction

There have been two encounters now where Matt said if the players had gone about them differently, they would have become next campaign antagonists.

I do not think it's really possible to consider the preps of Critical Roll to any normal table. Because it's their job. They can spend time again and again and redoe and recycle and lose work and barely feel it.

We normal DMs do it in our spare time. Not only are we not paid for it one way or another like Matt (which benefits greatly now of his preps per CR's moneymaking) but our free time is limited as it is. That's why you shouldn't over prepare. To not lose whatever preps you managed to squeeze out of your scheduling,

But even keeping encounters just in case is a 5 out of 10 idea. In the sense that where players are, what level they are, what equipment they got, the terrain, type of enemies, etc. is still improvisable in the same quality as adapting a cookie-cutter encounter to where they are would be. At least for me. Recycling and improvising sometimes takes just as long.

I will be saying that if I would be making money out of my preps, I would prep a lot more. And depending on how much money, if it can be enough to live on, I could prep for hours and hours everyday to have every situation covered and not feel it as much when things go in a way where 3 hours of my time go in a puff of smoke.

I mean, you should have the current adventure planned. That's probably ten sessions, right? If it's a bigger dungeon it might be 20 sessions.

Do you send your players into a dungeon without designing the dungeon first? What the fuck.

You should also always have at least the beginning of the next adventure planned, because at any time, the players might decide to give up on this one and move on to the next one. This could happen because they run out of clues, or because they think it's less important than their other goals, or because they disagree with the NPCs trying to get them to do it or for some other reason. They could also try to do the next adventure and this one simultaneously, especially in an urban campaign where everything is happening pretty much in the same place.

Stuff you planned that the players don't do is WAY better than stuff you didn't plan that the players do.

Lol