GMs: Improvise with a Simple Trick

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Aug 29, 2025

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Improvise Better with the Best Case/Worst Case Die Roll

If you happen to be a stand-up comic or an actor, improvising is possibly quite easy for you. However, most game masters are not comics or actors.

Learning how to improvise is incredibly helpful for GMs. Unfortunately, it can be challenging, especially if you are introverted or shy.

But it’s not impossible — anyone can improve their improvising skills.

Why Improvising Is Important for Game Masters

Improvising at the table allows you to use the best stuff that comes from your players. New plots emerge, and twists can be exploited. Ideas your players have can lead to new adventures and situations you never dreamed of.

Also, improvising cuts down session prep. Just got married? Is your job crazy? New baby? Improvising at the table frees you up to do other things instead of spending hours prepping.

One of the worst things a GM can do is over-prep, only to have the players ignore all that content. Improvising ensures this does not happen.

The Best Case/Worst Case Die Roll

One way to improve your improvising skills is to use a simple dice mechanic. I discovered this some years ago when running an impromptu session. I had nothing planned but wanted to have fun.

More importantly, I wanted my players to have fun. So I began doing something that has become known as the “Best Case/Worst Case Die Roll.”

When a Player Asks a Question

If a player asks you questions like, “Who runs the thieves’ guild in the city?” or, “How long does it take to get to the ruin?” — don’t answer. Have the player roll 1D6 first.

Results of the roll:

Worst Case
Very Bad
Bad
Good
Very Good
Best Case

Here’s where improvising becomes easier.

Use the result to shape your answer. A roll of 1 should be the worst possible scenario. A 2 is very unfavorable. A 3 is slightly bad or unfortunate. A 4 is decent. A 5 is very favorable. A 6 is the best possible outcome.

Encourage the group to help you come up with a fitting situation that matches the roll and run with it.

Example

Player: “Who runs the thieves’ guild in the city? I’d like to make a deal with him or her.”
GM: “Roll Best Case/Worst Case.”

Player rolls…

Your estranged sister who hates you and is now a chaotic evil serial killer.
A man you had thrown into prison years ago.
A surly thief who hates visitors.
A good-natured rogue always looking to deal.
She’s heard of you and would like to help if profit is involved.
A childhood friend who is more than happy to help.

Sometimes the same outcome could be either best or worst case. For example, if a player asks, “Is the door locked?”

Best case: Yes, if it means the room hasn’t been looted.
Worst case: Yes, if the characters are being pursued by a cave troll.

Example from an RPG Session

Here’s how a Best Case/Worst Case roll played out in one of my sessions.

We were playing D6 Star Wars. The party was a smuggler and his crew who occasionally did missions for the Rebel Alliance.

The group was tasked with recovering stolen information from another smuggler. The rebels gave them the coordinates of the ship’s route, so our heroes set a trap.

At this point, one player asked who the NPCs worked for. I said some crime boss. He then asked for a name and details, because his character might be familiar with crime bosses in the Outer Rim.

This was a great opportunity for twists and complications, but I hadn’t planned this mission. So, I told him to roll Best Case/Worst Case.

He rolled a 1. Everyone groaned. Worst case.

I asked him: “Who would be the worst crime boss the NPCs could be working for?”

He thought for a moment and said, “The one I owe 25,000 credits.”

In that instant, a simple mission became a living story.

His crew now had to raid a ship belonging to a crime boss who held the title to their freighter. They couldn’t be recognized. They had to prevent any messages from being sent during the raid.

Then another player asked: “If the ship belongs to the crime boss we work for, do we know the other crew?”

Hmm… roll Best Case/Worst Case.

Relax, Have Fun, Improvise

As you can see, this simple dice mechanic can be a great help in improvising and adding complications to adventures.

Give it a try in your next session and see what happens. It may take a little getting used to, but it should cut down your prep time and provide plot twists you couldn’t have thought of on your own.

If you want more GM tips, check out my book: The No-Prep Gamemaster: Train Your Brain to Run Tabletop Roleplaying Games

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