A Slick Three Step Wandering Monster System
Roleplaying Tips Newsletter #0775
A Slick Three Step Wandering Monster System
Ever since running B1: In Search of the Unknown I’ve enjoyed wandering monsters. As PCs quested for the legendary treasure of Roghan and Zelligar, I’d roll and run all sorts of monster encounters. It gave me yet another opportunity to be creative during the game.
This month’s RPG Blog Carnival hosted over at Moebius Adventures is Things in the Dark. To celebrate the carnival, today’s Musing is about the PCs’ worst fears — unexpected dangers in dark dungeons.
While it was fun rolling on the monster tables in B1, I’ve evolved my approach since then. Because wandering monsters give us several benefits.
They reduce your prep time.
They present an interesting challenge to PCs who otherwise would just have the run of the dungeon.
And most importantly, when done a certain way, wandering monsters prevent railroading while providing you awesome, plot-based encounters.
Here’s how.
Step One: Build Your Local Wandering Monster Inventory
In any given milieu, you’ll have creatures and NPCs living, surviving, and fighting.
Start with those and build a list of potential encounters.
Creatures gotta leave their lairs sometime to eat. Other foes need to raid or explore. Some need mates. Others are just curious or need to patrol.
Look at all your planned encounters and add those that might leave their 10’x10′ room for awhile, even if it’s just to stretch the legs.
Make a list. Keep your list regional. For example, you might make one list per dungeon level. Or you might draw an X through the forest and make one list per quadrant. Ditto neighbourhoods.
Think (briefly, don’t get caught in the weeds) of the ecosystem. Keep it simple with three tiers. Start with apex predators — beasts and monsters. Then add their food — lesser predators and prey. Then add the clean-up crew — slimes, vermin, fungi, plants, etc.
You’ve now got several plausible wandering monster seeds. But these are just the locals.
Step Two: Expand Your Wandering Monster Inventory
Next, add in strangers. Dudes coming from outside. Here’s where you get key plot benefits with a little campaign curation.
Look at your factions. Who’s got a mission? Add those folks as wandering seeds.
Look at nearby settlements and dangers. Travellers, explorers, and the lost. Add in a couple of ideas from those parts.
Check your plots. The villain’s minions shall wander and perform dirty deeds done cheap.
Check your Cast of Characters. Who would be interesting to encounter? Find forgotten NPCs who would surprise the PCs. Add in rivals co-questing. And look for NPCs who could stir the plot.
Factions, neighbours, plots, and cast inject your wandering monster tables with all kinds of opportunities to keep your story developing without wasting time or derailing the game. Much fertile ground here.
Step Three: Add Activities
You should now have a list of monsters, friends, neutrals, and foes that could stumble into the PCs in the dark.
This next step is important for making your table more than merely itinerant XP.
Either give each entry an interesting activity or create a table of random activities and roll along with what wandering monster gets encountered.
When you combo your monsters with their own gigs, you offer players hooks, you give yourself more material to improv with, and you add depth to your milieu.
For example, d6 possible interesting activities:
- Fighting another wandering monster
- Scouting or spying
- Stealing something or has just stolen something
- Stalking another wandering monster
- Playing with or teaching others
- Delivering a message or package
Activities add a fascinating dimension to your encounters. They can springboard new encounters or plots for you. And you can loop in existing campaign plots for story progression.

Wrap-Up
Trim your list. Toss boring ideas. Polish remaining ideas as desired.
Make a table and add a die roll column if desired. You can also just pick from your table during the game based on context.

Bonus Round
Got an extra five minutes? Here’s a bonus step that turns your wandering monster table into a delightful plot machine.
Rewind the calendar. Roll on the table. What happened? Turn this into a two-sentence backstory: what was the encounter and what were the results?
“A small group of trogs go to the pool for water and encounter the villain’s mercenaries doing the same. The mercenaries barter with the trogs and learn a couple of their words.”
Advance the calendar one day. Roll again or pick from your table. Progress your backstory.
“A trog tracks the mercenaries to their camp and spies. He’s caught and taken prisoner.”
Repeat a few more times, if possible.
Now what you’ve got on your hands is a situation the PCs step into. Use your storytelling skills to make the situation red hot and good for gameplay. Use your wandering monster table to generate as many backstories and plots as you like for the characters to encounter and unravel!