In any system that’s based on an edition of Dungeons & Dragons, the concept of dungeon crawling is almost integral to the experience. There has been a recent interest in the concept of dungeon turns, which traces its roots back to the earliest editions of Dungeons & Dragons where turns were taken in 10 minute integrals.

I wanted to provide the dungeon crawling mechanics I use in my Level Up: Advanced Fifth Edition game using Voidrunner’s Codex. Since this is a sci-fi expansion to the system, I decided to call this Derelict Crawling to stay a bit more thematic.

Going forward, you can equate to any usage of the word ‘Derelict’ as you would a ‘Dungeon’ in typical fantasy RPGs. A derelict doesn’t necessarily have to be abandoned. In fact, many are occupied by interested factions or strange alien creatures. These rules can also be utilized in locations you would very well not consider derelict, such as a colony outpost or research facility, and those locations would likely benefit significantly from the Alert Levels mechanic described later in this post.

This post assumes you are in a smaller location where your players are traversing a location room-by-room. In situations where they are in a larger derelict space station that’s several miles long, these mechanics would likely become tedious or boring, and would be better suited to a point crawl. This will be explored in a future post in how to adapt these mechanics over longer travel times between interesting locations.

Derelict Crawling Mechanics

When exploring a derelict, each action a player character makes takes 10 minutes, and these are performed in 10 minute rounds. In each round, each player declares what they are doing for that round and makes a check, and each check is done simultaneously. Since the check represents an action that takes over 10 minutes, features or psionic powers that give a bonus to a single roll are not applicable.

Ability Checks: The player describes want they want to do, and the Narrator determines if a check is appropriate. The Narrator then informs the player what ability score and skill combination is appropriate. If two players want to perform the same action, one would give the other the Help action. If more than two players want to perform the same action, then this would be resolved with a group check:

• If all players pass, the check is a critical success.
• If the majority of players pass, the check is a success.
• If the majority of players fail, or there are an equal amount of failures and success, the check is a failure.
• If all players fail, the check is a critical failure.

Combat: While the actual combat encounter will likely only take 6-30 seconds to resolve, treat it as taking 1 minute for easier tracking. This can be justified by the lead up to the encounter and the immediate aftermath taking additional time.

Movement: There are three speeds that players can traverse a derelict: slow, normal, and fast.

• Slow: This speed can only occur when players are exploring each room. Exploration of the room takes 10 minutes. If they spend no additional time in this room and move to the next, movement to the following room is included in that 10 minutes.
• Normal: Moving from one room to the next takes 1 minute and is unexplored. They have a -2 to passive Perception, and do not notice any traps. Additionally, if you are using the Alert System (described below), roll 1d6. On a result of 5-6, the Alert Level increases by 1.
• Fast: Moving from one room to the next takes 30 seconds. They have a -5 to passive Perception, do not notice any traps, and have disadvantage on any saving throws made from any triggered traps. Additionally, if you are using the Alert System (described below), roll 1d6. On a result of 4-6, the Alert Level increases by 1.

Random Encounters: Roll 1d6 for random encounters every hour, triggering a random encounter on a result of a 6. If utilizing Alert Levels, use the frequency and chance to trigger a random encounter as described by the current Alert Level.

Optional Mechanic: Alert Levels

If your derelict is actively being guarded and occupied by a hostile force, they will react if the players perform any actions that make them aware of their presence. To abstract this, you can utilize Alert Levels when it becomes applicable. Most locations should begin at Alert Level 1, but you can always start at a higher Alert Level if the situation calls for it.

• Alert Level 1 (1 Encounter/1 hour): The guards are unaware of the party and are not actively searching for them. When making Stealth checks, players roll against their passive Perception.
• Alert Level 2 (1 Encounter/1 hour): The guards are aware of a presence on the derelict, and are actively searching for them. When making Stealth checks, players make a contested roll against the creatures’ Perception.
• Alert Level 3 (1 Encounter/30 minutes): The guards have identified who has infiltrated the derelict and are on high alert. Frequency of random encounter checks double.
• Alert Level 4 (1 Encounter/30 minutes): The guards have identified who has infiltrated the derelict, and generally knows where the party is. Increase the chance that an encounter is rolled. For example, if you are rolling 1d6, and a result of a 6 would trigger a random encounter, increase the success range to 5-6.

Beyond the movement mechanics, other things can increase the Alert Level. Breaking down doors, using thunder damage, failing an Intelligence (hacking tools) check, or any other action that would bring attention to the party increases the Alert Level by 1.

There can be additional consequences at higher alert levels as well. More doors can suddenly be locked, anti-personnel turrets can be deployed, etc. In particularly secure and occupied locations, it would make sense that traps only become activate-able at higher alert levels, as the security team engages them to try to catch the party for their forces to appear. I would recommend these types of scenarios to occur on Alert Levels 3 and 4.

Decreasing the Alert Level

There are many ways that your players can also decrease the Alert Level, and this will largely be determined by the Narrator’s discretion. However, some ideas to keep in mind:

• Using the hacking maneuver implant data on a security camera, terminal, or other similar device to convince the guards that the party is no longer there, or any other creative tricks the party comes up with to deceive the guards.
• Disabling the security system. While this would not in-fiction reduce the alert level, it will mechanically have the same effect as the guards will have greater difficulty locating the party.
  • Instead of reducing the Alert Level, you can alternatively treat any stealth checks as if the party was moving at one movement speed slower. For example, if they are moving at a fast pace, use the passive Perception and Stealth check mechanics of the normal pace. If they are moving at normal, use the passive Perception and Stealth check mechanics of a slow pace. Finally, if they are moving at a slow pace, give them advantage on Stealth checks.
• Persuade, intimidate, bribe, or otherwise convince a guard to reduce the Alert Level.

Other Systems

These mechanics can obviously also be used in 5e-based fantasy games using Level Up: Advanced Fifth Edition, Tales of the Valiant, Dungeons & Dragons, etc., or adapted to non-5e based games. As long as your goal is to be able to effectively manage the time your party takes in a dungeon and adjudicating threats and consequences, a version of the above mechanics should prove helpful.