Exploring dungeons is an iconic part of old school roleplaying games. The guidelines in this section will help the referee run adventures in dungeons, castles, caverns, and other “indoor” spaces in Dungeon Delving Undying Light.

Light: Humans and many other races require a light source (or magical ability) to see in the dark. Torches, lanterns, etc. will produce limited areas of light (generally 20 feet of bright light and a further 10 feet of dim light), but they also make it easy for monsters to see the party coming, making surprise impossible. Torches can be blown out by strong gusts of wind (d6 roll: blown out on a 1 or 2). Lanterns use flasks of oil as fuel, and a lantern can burn continuously on 1 flask of oil for 24 turns (4 hours). Torches burn continuously for 6 turns (1 hour) before burning out. Most monsters living in a dungeon have infravision or some other means of seeing in the dark; however, these methods do not work in the presence of a light source.

Seeing Monsters: Unless surprised, characters will see monsters when they are 2d6 x 10 feet apart. Surprise distance is 1d3 x 10 feet.

Wandering Monsters: The referee should roll 1d6 every 2 turns for wandering monsters (more often if the party is making a lot of noise or otherwise attracting attention). On a roll of 6+, wandering monsters stumble across the party from a random direction and distance.

Avoiding Monsters: Unintelligent monsters normally attack, try to run away, or continue what they were doing ignoring (actually watching warily) the characters. Intelligent monsters may follow their orders, make a reaction check, automatically attack, etc. depending on circumstances. Unless surprised, a party may try to flee to avoid a battle. Monsters will generally pursue if there is less than 120 feet between the two groups. Monsters will only pursue around a corner or through a door on roll of 1 or 2 on a d6 (1 if a secret door is used). Fire will deter many monsters. Food will distract many monsters: unintelligent monsters on a 2+ (on a d6), semi-intelligent monsters on a 4+, intelligent monsters on a 6+. Treasure may also distract monsters: unintelligent monsters on a 6+ (on a d6), semi-intelligent monsters on a 4+, and intelligent monsters on a 2+. All chances may be adjusted by the referee depending on circumstances. These same rules determine how monsters will pursue if the characters disengage and retreat (or rout) from a battle.

Rest: One turn in six must be sent in rest or all characters suffer a -1 to all d20 rolls and to damage rolls per rest missed. Time spent searching is not time spent resting.

Doors: Dungeons often have many doors, some secret and others obvious. Many are locked, and a thief will need to attempt to pick locks. However, characters can attempt to break a door down. In this case, the player rolls 1d6. A result of 5+ means the door has been broken down. Strength bonus (if any) is added to the number rolled.

Players will sometimes want their character to listen at a door to hear any noises beyond. Again, the referee rolls 1d6. A roll of 6+ results in success, and a roll of 5+ succeeds for demi-humans due to their keen hearing. A thief is specially trained for this task, and uses his Hear ability. This attempt may only be made one time at any door by a character. Note that some creatures, such as undead, do not make noise.

Traps and Trap Detection: A trap will usually spring on a d6 roll of 5+ when a character passes over or by them or otherwise triggers them.

Characters of all classes can search for non-magical traps. All characters except dwarves and thieves can succeed in spotting a trap on a roll of 6+ on 1d6. Dwarves succeed on a roll of 5+ on 1d6. Thieves are specially trained for this task, and use their Thief Skills ability. Players must declare that their characters are actively looking for traps, and they must be looking in the right place. This roll may only be made once in a particular location, and it takes 1 turn per effort made. Since the referee rolls the dice, the player never know if the roll failed or if there simply is no trap in the area searched.

Secret/Hidden Doors: Secret (and hidden) doors can only be spotted if characters are specifically looking for them. The referee rolls 1d6 when a player declares that his character is looking for secret doors. A result of 6+ is a success, except that elves have better vision and succeed on a roll of 5+. Thieves are specially trained for this task, and use their Thief Skills ability. A character can only attempt to look for secret doors once in any given area, and it takes 1 turn. A second attempt cannot be made in the same area. On a roll of 1 on 1d6 an Elf will notice a secret door even if he is not actively searching for secret doors. Since the referee rolls the dice, the player never know if the roll failed or if there simply is no door in the area searched.