Dungeon Exploration

When the characters explore a location, they seek to gain information and uncover secrets against the backdrop of an ongoing threat. In classic dungeon exploration, the characters must weigh the dangers of encountering monsters against the benefit of searching for secret doors and traps. A group that moves quickly has less risk of an unexpected fight but at the risk of blundering into a trap or overlooking a critical piece of information.

Elements of Exploration

In my games, I’ve discovered that exploration needs a few key pieces to make it work.

A Threat

What’s the risk in exploring an area? What can go wrong? How do the characters’ actions affect that risk? Exploration needs an active threat to keep the players on their toes and add dramatic tension to play. Without it, exploration turns into a dull series of die rolls.

A Goal

What do the players want? What’s the benefit of exploring an area? The players need to understand what they are looking for to frame the action and provide clear signs of progress.

What These Rules Do

This framework for exploration is designed to create a looming, growing threat that increases tension over time. It provides a timer that reflects the growing danger of the environment. It leaves the specific goal up to the players or the DM’s presentation of an area.

This specific set of rules draws on the system I’ve used for dungeon exploration over the past few months. I’m still working on expanding it to outdoor exploration and other, larger time and distance scales.

The Exploration Round

An exploration round represents 1 minute of action. During this time, the characters have a chance to search for secret doors, move, and otherwise interact with their environment. Meanwhile, the location’s looming threat grows as the characters explore. The round is broken into the following steps.

Threat Step

Threat represents the dangers present in a location. When exploration begins the threat is usually set to 0. Certain actions, events, and encounters increase threat.

Each location gives details on how to resolve threat. It might also specify checks or other special steps to take during this step.

Managing Threat. I find it helps to place a d6 in front of the players to remind them of how much threat they have built up. I also add narrative cues and adjust my descriptions to match the rising threat and give a hint of its nature. For a subtle threat, I might not even tell the players why I am piling up d6s until I roll them. In other adventures, I make it explicit what the growing pile of dice represent.

Resolving Threat. To resolve threat, roll d6s equal to the current threat. For each die that rolls a 6, consult the encounter table to determine what happens this round.

Group Checks. During this step, the characters might need to make a group check. Each character makes the same check against the same DC. If half or more of the characters succeed, the group succeeds. Otherwise, they fail.

Group Checks and Expertise. If at least one character in the party has Expertise in the skill used for a group check, characters without Expertise have advantage on their group checks.

Group Turn

After the threat step, the group takes a turn. In exploration, the characters work together. The DM asks each player what they want their character to do over the course of the minute, including movement. The party collectively decides how many moves and actions they want to take, up to 10. The DM then resolves any checks as needed.

Movement

The party can move once. Each time the party moves, each character can move up to their speed.

Faster Movement. The party can risk moving faster if they want, as 1 exploration round equals 10 combat rounds. The party can move up to 10 times, but the party gains 1 threat for each time they move after the first.

Actions, Spells, and Other Activities

During an exploration round, the party can take one action. When the party takes an action, each character can do one thing, such as inspecting an object or casting a spell. A character can complete any task that takes 1 minute or less to complete when the party takes an action. Longer actions that take more than a minute require multiple rounds of exploration.

Extra Actions. The party can choose to take extra actions, taking up to 10 actions during a group turn. Each time the party opts to take an additional action, they gain 1 threat. The additional actions must all be completed in one minute.

Scout. A character can choose to act as a scout as the group travels in place of taking any other action. They do not need to make checks to detect creatures, traps, or other threats. If their movement or activity, such as opening a door, would trigger a trap or reveal a monster, they make the relevant check to determine if they spot the threat. If so, they learn of the danger before triggering it and the party can adjust their plans accordingly. Otherwise, they complete the action and provoke the trap, encounter the creature, and so on.

Watch. A character can choose to act as a keep watch as the group travels in place of taking any other action. A character who opts to watch gains advantage on all Wisdom (Perception) checks and initiative rolls until the start of the next group turn.

Encounters

If the party meets a creature or triggers a trap, run an encounter using the standard rules as normal. The location details how an encounter might affect threat.

Example Threat: Wandering Monsters

Here’s an example for the typical dungeon that uses wandering monsters in the style of old school D&D. In this example, the dungeon level is controlled by a gang of orcs who jealously guard a magical gem that the characters seek for a ritual.

Threat Step

At the start of the threat step, roll threat. If the threat is 0, roll one die. Count the number of 6s rolled to determine what happens.

One Six: The characters hear orcish voices in the distance or other signs of orc activity. Add one threat.

Two Sixes: An orcish patrol approaches. 1d6 orcs are 60 feet away from the party, in a random direction. They move 30 feet toward the party at the end of this round.

Three or More Sixes: Two orc patrols approach. As above, but two groups approach in two different directions or one large group that consists of both patrols combined if there is only one path heading to the characters’ location.

When an orc patrol encounters the characters, they attack unless the characters come up with some way to convince the orcs that they belong in the shrine. If a fight starts, the orcs run to fetch reinforcements once half or more of them are defeated.

Threat Six or Greater

Once the overall threat is 6 or higher, the party must make a group Dexterity (Stealth) check at the start of each threat step. On a failure, increase the threat by 1.

Threat Twelve or Greater

At threat 12 or greater, if an orc patrol appears increase its numbers by an additional +3.

Encounters

If a fight breaks out, add one threat at the end of each round unless the characters somehow limit the sound or other disturbance the fight creates.