You roll for random encounters wrong (and so do I)

Original Dungeons & Dragons made rolling for wandering monsters more a core part of play than rolling a d20 to hit—d20 rolls were in the optional combat system that everyone used. Over the years, as D&D evolved, random encounters fell from favor until they neared extinction. In second edition, DMs emphasized story and saw random events as an unwelcome distraction. By fourth edition, battles consumed so much time that one random encounter could devour a session.

Random monster

Random monster

The designers of fifth edition recognized the value or random encounters: The threat of wandering monsters gives players a reason to hurry and to avoid the 5-minute adventuring day. Random encounters make distance and travel meaningful. See “Three unexpected ways wandering monsters improve D&D play.”

Traditionally, dungeon masters roll for random encounters during a session, behind the screen.

With players accustomed to this secretive approach, a DM can ignore die rolls and script every wandering monster in advance. Their players will never know.

I have a confession. Sometimes I roll random encounters before a game session so I can grab the monster miniatures that I need. By rolling in advance, am I diminishing the game? What if I just skip the rolls entirely and choose “random” encounters that suit me?

I my last post, I considered the advantages of using random rolls to shape your game. One benefit is that die rolls separate the players’ success or failure from the game master’s fiat. This benefit only comes if you make die rolls in the open and if players have a sense of what the rolls mean.

Few rolls swing the course of the game more than those for random encounters, so making these rolls in plain sight makes sense. But unless the players know what a roll means, the DM may as well pretend to read tea leaves. The chance of an encounter qualifies as secret information for the DM, so rolling for random encounters conflicts with the benefit of open rolls.

Nonetheless, a DM can reveal enough to make open encounter rolls meaningful without spoiling secrets.

Player characters exploring a dungeon or wilderness probably have a sense of what inhabitants they could encounter. Underground, investigators notice either dust and cobwebs or signs of traffic. In the light, rangers and druids know an idyllic path from monster infested wilds. Some PCs bring backgrounds or skills that give more insights. PCs may know a place by reputation. As a DM, you can rely on all these factors—and possibly on some checks—to gauge what to reveal about potential random encounters.

In the past, I would relay such information purely in terms of the game world. “As you travel the Stranglewood, you see signs that confirm its reputation for monstrous predators.” Now, I might add some game mechanics to the flavor. “For each day of travel, you could encounter wandering monsters twice. I will roll on a D20. Higher rolls lead to encounters.” These details help players decide strategy, and players enjoy strategy over guesswork. Plus, players endangered by wandering monsters will  act with urgency.

Some dungeon masters worry that revealing the mechanics of these rolls spoil too many secrets, or that it foils the players’ sense of immersion. I used to agree, but a Living Forgotten Realms adventure changed my opinion. In Agony of Almraiven, players face the challenge of freeing a brass dragon from a net as Thri-kreen harass the beast. The encounter combines a skill challenge with a combat encounter. Before I played this encounter, I disliked it. I hated the mechanical artifice of skill challenges, and this one came with a handout that let players check off their successes. Still, I dutifully handed out the sheet and let the players tackle the skill challenge as a game within a game.

Players loved it.

I ran Agony of Almraiven six times, and every time the players relished this challenge. The experience did little to improve my opinion of skill challenges, but it reversed my opinion of occasionally letting players glimpse the nuts and bolts of an adventure. Players enjoy immersion, but they also enjoy playing the game as a game. For example, players can immerse themselves in combat encounters even though they know all the rules behind them.

The original D&D game exposed the mechanics of wandering monsters without making play less compelling.

For random encounters to benefit your game, players need a sense of the threat of wandering monsters. Don’t show your encounter tables, but do explain that an hour delay leads to another roll, and that if you roll a 20, they will probably meet something nasty. Then roll in the open.

Have I dropped my practice of pre-planning random encounters? Not entirely. I strive for some transparency, rolling in view to see if an encounter occurs. As for the specifics, I might roll and prepare a few options in advance. During the session, I let the dice choose among those I prepared.

Note: The random encounters in an upcoming Adventurers League Expedition inspired this post and the last one. Will this adventure benefit from its randomness? I don’t know. In a convention setting, time and pace pose the biggest challenge, and random encounters make pacing harder. On the other hand, I always learn something when I run something new, and I’ll be running the final version of that Expedition a few times at the Winter Fantasy convention. As always, I hope to see some friends of the blog at my table.

9 thoughts on “You roll for random encounters wrong (and so do I)

  1. Geoffrey Greer

    Good thoughts, David. This goes hand-in-hand with an article I read recently about keeping the pressure on for the PCs, specifically in terms of not letting them simply “rest and recharge” whenever they want without the consequence of the passage of time. I forget the author now (was it you?), but one potent statement made was that “an RPG is a game of attrition,” and that expending resources needs to be economized, with the players bearing the future in mind.

    1. DM David Post author

      Hi Geoff,
      Thanks for commenting. I didn’t write that article, but it sounds like something I wish I had written. Adventure designers seldom do enough to maintain time pressure on the PCs.


  2. Justin

    I use random encounters during every rest, long or short.

    *Normally* nothing will happen, or nothing that’s not easily handled by a sentry (like some low-end creeping vines), but it keeps my players on their toes..

    1. DM David Post author

      Hi Justin,
      I like the idea of making a routine out of checking for random encounters during every rest. That policy makes the players weigh the benefits and risks of each rest.



    The 2nd edition DM’s Guide had tables for wandering monsters including what dice to roll and at what times depending on the terrain. I still use these tables even now. I also roll up random monsters ahead of time and make a table with them. If the dice roll indicates a random encounter I roll 2d10 and see what comes up…

  4. Vichrae

    The title seems click-baity, as I didn’t see anything about what I’m doing wrong with random encounters. My players know how often they’ll roll (I have them make the rolls) and what results in an encounter, but don’t see my tables. Sooo…?


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