There is a classic problem for all DM/GM/Refs which is, "How much prep is the right amount?"

I want to walk through the considerations in my mind.

Comfort With...

The System

A lot of low-prep advice comes with an assumption that you are fluent or highly familiar with the rules. I say this because they often talk about being able to improvise a lot in the moment. This is really hard to do if you're also stuck referencing rules all the time.

There is another school of thought here that treats the rules of the game you play as guidelines and as long as nobody realizes you're making it up or the table is cool with it, then its fine.

So if you aren't comfortable with the system you can leave more headspace to improvise. If you aren't comfortable with the system, you don't have that headspace. You'll need to prepare more because you need to reference rules more often.

The Setting

This is where a lot of the low-prep stuff really shines. The more comfortable you are with the setting, story, etc. the easier it is to improvise around it. This works well in homebrewed worlds and settings, but gets harder if you're using some other material.

One interesting thing though is that if you're running a longer-term game, the more you improvise means the better you need to be at taking notes. That random "googah" you described as a interesting detail has a funny way of emerging over and over again.

Winging-it in a setting that isn't yours is absolutely do-able, but the problem is that you don't always know if you are improvising on top of something that exists that you've forgotten or simply not bumped into. Suddenly an act of convenience and laziness puts you in a corner when you have to justify the thing you made up against the writing on the page and the consequences of it.

Game Type...

More Tactical

This is where traditional D&D, Pathfinder, and other games sit. They offer countless rules, and additions, and supplements to the game that makes it impossible to keep in your head. The more tactical the game gets in terms of mechanics, the harder it can be to improvise since there are many rules to consider at once.

A good rule of thumb is to improvise around the parts that you are certain about. Some folks know, for example, the stats of certain creatures and are fluent in combat and spells. They can improvise a number of encounters around it. Others might know only spells, so they can improvise around what spells a creature has and what they do.

More Narrative

More narrative based games tend to favor low-prep style work, but that isn't always the case. Consider a murder mystery or a thriller type story. Often these benefit from having clues, dead ends, and richly developed NPCs.

While that type of prep might be much lighter than a more tactical game, a more narrative style game doesn't mean you can avoid prep altogether.

In fact, a more rules-lite, narrative game simply shifts the preparation to other areas like NPCs, interactions, and the like. I'm horrible with NPCs, so I have to keep this in mind when I prepare games that are like this because it can leave the game feeling really empty and thin without that richness.

What to Prep

Well, an answer that I think is good to start with is, "Whatever you're bad at." If you're really good at improvising evocative detail, you don't need to prep it. If you don't know the rules well, prepare a reference sheet or GM screen specific to the parts you mess up. If you're bad with NPCs, prepare some.

In general though there are some ideas that folks do keep coming back to that you may want or not want in your own prep.

• Interesting locations
• Interesting NPCs
• Outline of overall plot
• Rumor tables
• Encounter Tables
• Maps

Some of this will matter to you and some won't. It depends on the game you're running, your strengths, and the underlying system.

Mystery and Thrillers...

In my experience one of the best things to prepare for this type of game is called a Clue Map. In essence it is a simple map (Or graph if you're in software) that organizes the game around the clues, how they connect, and how you find them.

Think of it like a point-crawl, but each point is a clue.

Hexcrawls and Sandboxes...

This is the type of game I like but is classically heavy on the prep. First and foremost, you need a map. In the beginning only major things need to be there.

From here, you can simply work in advance of your party by preparing the things in front of them a session in advance.

A good way to think about this though is you are preparing tools and assets to "drop-in" to your game. That means you might prepare 20 or so NPCs to have at the ready. You might prepare 10 monster lairs that you'll use when they bump into one randomly. You might build out dungeons to drop into a place you decide needs one.

Your Notes...

Imagine you're sitting at the table or at your VTT. How do you, as quickly as possible, locate the information you've prepped, read it, and communicate it back?

It can be fun to write your notes in descriptive prose, but I'll recommend against that. Instead, focus on shorthand where only the main elements get words. You can add structure to this by using an outline type structure too. Let me give a quick example.

Before
The crumbling tower that has stood for centuries reaches about 45 feet into the air. Its roof is half-collapsed and its rafters are now the home to numerous birds.

After

• Crumbling tower, 45ft tall
• Half-collapsed roof
  • Birds nesting in rafters

Now, admittedly the first one is fun to write and to read but not at the table. Pausing to read all of that, decide what is important, and communicating it back is really slow. Reading it out loud feels odd, and isn't often the intent.

So now we have the second one. It has a structure where the main elements are obvious, and the deeper the nesting of the outline goes the less obvious details are. This allows for quick scanning and improvising around the essentials without losing it, being quick to read.

Maybe you don't like the outline version, but one thing that does deserve your thoughtful attention is how do you make your notes work for you at the table when you're running it.

The Right Amount...

The right amount of prep depends on you, your strengths, the game you're running and more. I don't think there's a universal right answer, but I think if you focus your attention to the things that you're not good with and the things that slow you down, you'll find the right mix for you.

As a final note, there are likely elements of preparing a game that you really enjoy and the idea of forcing them into any one form diminishes it. Enjoy the parts you enjoy. When you're done, take the next step of making it ready for the table.

For me, I find I write in prose a lot easier than outlines when I'm exploring ideas and getting excited about them. I also know that is of almost no use at the table. So I will, at the last possible minute, put the outline version of it beneath my prose so I can run my game smoothly. Find what works for you!