A few years ago I created a campaign designed to work as a randomly generated "One-Off" D&D campaign. For those familiar with JADE you may recognize the name Ivershill, as that very game. In this game every encounter used a small three entry encounter table that I rolled on to determine the event, meaning that the opening Nine events of the game had 19,683 possible event combinations.
It has been a few years now since we played Ivershill, but the effect creating those small tables had on me as a Dungeon Master can not be understated. As time went on an we started JADE's long running Arachnophobia Campaign, and those small encounter tables followed me to that game, though this time I upped them to four entry encounter tables, and used them a little more sparingly to fill in the space between my scripted encounters.
Aside from helping me simulate a butterfly effect from the Time Travel featured in Arachnophobia, These tables also kept things very interesting and fresh for me as a DM. In the end I never actually knew with 100% certainty how a game would play out. A single event could alter the course of the campaign, and for me that was exciting! But of course coming up with all those unique events can be a challenge. That was why I settled on four entry tables: large enough that I can roll a d4 to determine the event, small enough that I will not spend most of my prep time making events that will not happen.
However even coming up with four unique events for every encounter can be a difficult. So I also came up with a rough guideline of the types of encounters every four entry encounter table should feature.
So here is what you need:
1. A Monster Encounter
Let's get this one out of the way. One of the events in your table should be an area appropriate monster that wanders into the area...Or a Wandering Monster if you prefer. And while the players may choose to work their way around the creature, fighting it should always be an option in this sort of event.
So if one of the encounters in your four entry table is a Wandering Monster, then that means there is always a 25% chance that your party will need to defend themselves.
2. A Gift
Things fall off the backs of carts all the time, and it is always surprisingly interesting to see how your players react. This can be anything from a gold ring, to a wheel of cheese, to a bag of severed human hands... Whatever fits the tone of your campaign.
These sorts of found items can spark some very entertaining debates among the players. I have heard group discuss whether they want to try and return the item, whether or not the item is booby trapped, whether they should even pick it up at all, etc. etc.
3. "Hey Look a Bird!"
A bit of an inside joke, but effectively this type of encounter is a description of the world around the players that is used to build atmosphere. So effectively it amounts to being about as important as "Hey look a bird!" These sorts of encounters are a great way to give your characters a break, and a moment to think about where they are and how their position has changed since the start of the game/campaign.
So change the weather, mention the mountains in the distance, describe a hawk that flies over the dense canopy above. Whatever suits the moment. Then take some time and ask your players about their character's thoughts and motivations. It will be a great break from combat and a good chance for your players to consider their characters.
4. A Small Side Quest
While larger side plots should be introduced through character interaction, a small event for the players to get wrapped up in is a great way to keep things fresh. This sort of encounter should be a a small mission that they players may either choose to ignore or complete. You know, the sort of thing you might find in a video game.
So you might encounter a young boy desperately pleading with passers-by to help rid his farm of bandits, or two merchants blocking the road with their carts and arguing over who crashed into who. The rewards for the players here are XP, a bit of money or items, and best of all potential allies as you help people and make friends. The downside is of course the expenditure of time on fairly meaningless matters, and the potential for harm, and making enemies.
Be sure as a DM that you do not bite off more than you can chew here. A side quest introduced in a random encounter should not take more than the rest of your current game to complete. It is supposed to be a small event to fit in between story encounters, not the game itself.
So there you have it! May four entry encounter tables change your games as much as they have changed mine!
Written by: Andrew Gregory
All images from D&D 5's Volo's Guide to Monsters