Tunnel Dungeon (RDG)

Tunnel dungeons are densely occupied labyrinthine networks teeming with humanoid inhabitants beneath the surface. Ever-growing due to the ceaseless activities of their denizens, the tunnels and rooms serve as homes, fortresses, and treasure troves. Occupants must protect themselves against threats from both above ground and below, often employing elaborate defenses, traps, and architectural innovations. While treasures abound, stirring up too much attention may cause a group of intruders to become overwhelmed by the sheer number of potential adversaries.

Entrances to these areas serve as pivotal junctures requiring protection to ensure the safety of the inhabitants, many of whom are likely non-combatants, including children, who contribute to the community's productivity. Multiple defensive measures are typically in place, encompassing strategies that may involve personal sacrifice and, crucially, the activation of an alarm. It's worth noting that not all entrances are externally guarded; some tunnel dungeons may appear innocuous to passersby. However, upon entry, individuals should anticipate encountering immediate resistance from defenders within the area.

However, exceptions exist to this pattern. Certain dungeons may remain undisturbed for extended periods, spanning months or even years, leading the inhabitants to grow complacent regarding the need for vigilance. While it's conceivable that a group could enter without encountering any resistance, such occurrences are rare.

Typically, guards or sentinels are there to apprehend intruders by surprise or to fiercely defend their territory if provoked. These are non-levelled, yet trained as soldiers, so that in addition to their hit dice/body mass they'll have 2-5 additional hit points from training. For example, a soldier hobgoblin has 1+1 HD and 1-8 h.p. per die, +2-5 h.p. for training, for a total of 4-14 h.p. They have a morale of 7 or better, depending on race.

1st Level Dungeon

Tunnel Dungeon Entrance

Entrances come in a variety of sizes and forms, serving as essential transitional points from the external environment to the interior of the dungeon. The design of these entryways necessitates a relatively modest outer footprint to avoid drawing undue attention to the dungeon, which could prompt intervention from influential local figures determined to eradicate any perceived threats. By maintaining a discreet external presence, these entrances help to minimize the risk of discovery and subsequent attempts to eliminate the dungeon's inhabitants.

Die rolls indicated are on a d20. Each percentage shown is rolled individually to see if that feature exists. All passages, unless stated otherwise, are 5 ft. wide.

Tunnel Dungeon Entrance

Roll	Result
01-23	Large opening into abandoned mine, either level or somewhat sloped (1-15) or occurring as a vertical shaft (16-20). May have covert sentinels (40%).
24-32	Palisaded yard, 20 ft. diameter; gate permits access, guarded by evident soldiers. May have one tower (20%). Sealed door into tunnels located within palisade. Replace palisade with stone circle 5% of the time.
33-93	Small opening, deserted and obscured by vegetation (1-9), amid scattered boulders (10-16), beneath a low, crumbling archway (17-19) or hidden beneath a rusted iron grate (20).
94	Submerged cave, accessible only by diving beneath the water's surface and swimming through a entranceway passage to an interior, breathable hewn passage.
95-00	Timbered door set into a rocky face of a cliff. May be barricaded (25%) and/or guarded by 2-4 evident soldiers (50%); otherwise deserted.

Large openings give way to a long undisturbed passage about 60 ft. in length, which must be traversed before learning what is in space beyond. Outside the abandoned mine, there are bound to be remnants of mine carts, with wooden structures, timber and scattered tools. An investigation should reveal that these have been moved or examined in the recent past. If there are covert sentinels, these are positioned discreetly, hidden from view among rocks or vegetation, watching the players and waiting for an opportunity to take them by surprise. If there are sentinels, roll on the humanoids level 1 table to determine race of humanoid for the sentinels for the habitat below.

Palisaded yards may be half-circles or three-quarter circles, depending on the terrain; the palisade is 15 ft. high. The dungeon door will give way to a 20 ft. passage that slopes downwards at 4-24 degrees. This door is 7 ft. high, 4 ft. wide and 4 in. thick; because it's in constant use, it won't be stuck, barred or bolted. Towers consist of a frame supporting a platform 20 ft. off the ground, 8 ft. wide, with a single archer on top if the tower is present; this is in addition to the 3-8 evident soldier guards that are present. Each is equipped with a horn for giving an alarm. There is a 10% chance for each guard that a chained watch animal is also present. If a stone circle is indicated, this is also 15 ft. high and 2 ft. wide; add an addition 2-4 evident guards. Palisades and stone circles also include a gong for giving an alarm. As with the covert sentinels above, roll to determine the race of the humanoid for this area and below. The total number of guards positioned outside the dungeon cannot exceed the total number of warriors.

Small openings are 2-3 ft. wide and always concealed, requiring 10 to 60 minutes to locate. They are deserted, without guards or sentinels, and are rarely used (if at all) by the residents. There is a 10% chance of a trap being located around the entrance. The narrow opening enters upon a similarly narrow passage that descends 4-10 ft.; from the bottom, the passage continues for 5-20 ft. before reaching the space beyond.

Submerged passages are completely full of water, which may be presumed to be clear. Torches and other illumination sources, however, cannot be lit on the other side without first having an opportunity to dry. The entryway descends 7-12 ft. downwards to a 4-6 ft. wide opening, which continues for 6-18 ft (4d4+2). They open at the top of a passage that's a mere 10 ft. before the inside space.

Timbered doorways consist of a dungeon door without fortification set into the stone exterior as an entranceway into the dungeon. If not barricaded or guarded, there is again a 10% chance of a trap. Inside the door is a 20 ft. passage leading to the inside space. If there are guards, as with the covert sentinels above, roll to determine the race of the humanoid for this area and below.

Initial Space Behind Entrance

This describes the area first encountered once passing through the entrance, occurring at the end of whatever distance has been described under the tunnel entrance, above. This area describes what additional defenses are positioned between the characters and the interior of the habitat, if any. As before, passages are 5 ft. wide and where indicated, are 20 ft. long before a check on the periodic check table is made, below. Where a door is opened, check afterwards on the space beyond door table.

Tunnel Dungeon Entrance

Roll	Result
01-06	Alarm; bells and other devices have been rigged throughout the passage to alert inhabitants once an entry has been made.
07-45	Guardroom; 15 ft. diameter circular room with 2-3 soldiers that have been posted to monitor and control access to the habitat. Open to the approach passage. Includes furniture, one dungeon door on far side.
46-60	Obstruction; bars passage, providing 2 archers cover equal to +6 AC, with an additional guard to raise the alarm, as with the 'guardroom' above. Passage continues beyond obstruction.
41-69	Passage; undefended. There are signs of evident travel over the surface of the passage, but there are no defenses of any kind in place, not even a trap. Make periodic check at end of passage.
70-93	Portcullis; bars passage, with single guard on duty to raise the alarm, as with the 'guardroom' above. Passage continues beyond the portcullis.
94-97	Reinforced doors; open, attended by two guards, who are ready to seal them against intruders as soon as they're able; characters must rush forward to arrest the doors before they close, as they will lock in place once shut.
98-99	Trap has been placed in passage; consult trap table. Trap may be place at any point along 20 ft. passage.
00	Watch beast has been chained here to guard passage; the beast will fight to the death. Consult trained animal table.

Alarms are clearly visible, serving as a deterrent by their mere presence. Most unintelligent creatures will likely ignore them and trigger the alarms. Navigating through the area without setting off the alarms requires both a dexterity check AND a saving throw vs. breath weapon; to remove the alarm requires an ability to remove traps. If an attempt to disable the alarm fails, a substantial amount of material falls to the floor, alerting the inhabitants to the presence of intruders.

Guardrooms may vary in shape but are typically small, as limited access is part of their design. The guards are likely to be bored from endless days of "watching," and must make a surprise check once player characters come within 40 feet. Players, as intruders, need not make this check. If the guardroom is at the head of a mine tunnel, or if intruders take time to pull themselves out of a submerged tunnel, the guards have time to recover. Otherwise, a party may potentially overwhelm them before they can act. When encountering intruders, one guard will rush into the habitat to raise the alarm, while the remaining guard or guards stay to engage in melee. Roll on the humanoids level 1 table to determine race of humanoid for the room and for the habitat beyond.

Obstructions clutter the passageway with tangles of wooden beams, piles of stones or stacked gabions (baskets filled with earth or stone) and fascines (bundles of sticks or rods tied together). These can be traversed, but doing so requires 10 action points (AP), however many combat rounds it takes. During this time, the character cannot engage in any other actions. As with the 'guardroom', roll to determine the race of the humanoid for this area and beyond.

Passages are genuinely undefended; note that "trapped" passages occur elsewhere. Although this may unnerve the party, it's evident that the dwellers have been undisturbed for so long that they no longer expend energy to watch over this part of their habitat.

Portucullises are heavy structures, typically made of wooden beams 2½ inches thick, with spaces 4¼ inches wide, providing cover equivalent to +3 AC. The gate can be lifted with the combined effort of up to three characters whose total combined strength is 42 or higher (count each 10% strength percentile as 1 point, so that 18/00 equals 28 points). This process takes three rounds, and the portcullis must be supported with a spike, strong beam or another comparable means to remain open. This gives plenty of time for the fleeing guard to raise the alarm. As with the 'guardroom', roll to determine the race of the humanoid for this area and beyond.

Reinforced doors are dungeon doors, each equipped with an iron peg on the far side that locks into the floor when closed, securing the door shut. Each door weighs 347 lbs. If the guards are surprised, they can be killed or the doors blocked before they can be closed. If the guards gain the initiative, they'll need 6 action points to fully shut the doors. This can be prevented by holding the door and successfully rolling to overbear, though the weight of the door counts in favour of the defenders. There is only enough time to observe that a passage lies beyond the doors, but no further details can be discerned. As with the guardroom, roll to determine the race of the humanoid for this area and beyond.

Traps within the lair consist solely of devices that residents can safely avoid while moving in and out. Characters with the knowledge to see simple traps can navigate around them effortlessly but cannot impart this skill to others. In certain instances, they may possess the ability to trigger the trap without sustaining harm, contingent upon the trap's design and their ingenuity.

Watch beasts are trained to react aggressively to strangers and cannot be negotiated with, nor swayed by offers of food or other distractions. During each round of combat against a watch beast, there is a 1 in 4 chance of the battle being heard. If a successful roll occurs, two archers will arrive on the third round thereafter and lend support to the beast. If the watch beast is slain before the archers arrive, they'll unleash two missiles before hastily retreating.

Monster Tables

Humanoids Level 1

Tunnel Dungeon Entrance

Roll	Monster	Warriors	Depen-dents	Weapons
01	Bugbear	1	0	godentag (1-10 damage +1 for strength)
02	Cavewight	1	0	spear (1-8 damage +3 for strength)
03-06	Dwarf	4-14 (2d6+2)	6-21 (5d4+1)	battle axe (1-10), military pick (11); short sword & spear (12-20); archers use light crossbow.
07-08	Elf	3-11 (1d8+3)	4-15 (1d12+3)	long sword (1-6), short sword & spear (7-12), spear (13-20); archers use long (1-8) or short bows (09-20).
09-10	Gnoll	1-2	1-2	glave; archers use "great bows," a brief description of which can be found with the bows.
11-13	Gnome	5-15 (2d6+3)	7-21 (2d8+5)	club & spear (1-7), short sword & spear (8-20); archers use short bows.

To determine the experience level of characters who possess that distinction, roll a 50% chance progressively until failing. For example, Linn the fighter is 1st level; she rolls and succeeds, becoming 2nd; she succeeds again and becomes 3rd; then she fails at becoming 4th, setting her level at 3rd. Roll gender of warriors and dependents randomly. The highest level character in a clan is counted as leader, with commensurate benefits, with that having the highest charisma chosen among those at the same level.

Dependents consist of adult workers and elders, whose number is determined using the "warrior" column, limited by the maximum dependents already determined; these have h.p. according to their hit dice. Remaining dependents are children aged 0 to 14, whose h.p. equals the humanoid's normal hit die halved (fractions discarded) with a -2 modifier. Those with less than 1 point are too young to engage in combat; hit points for the remainder reflect their age and relative robustness; note that with some creatures, such as troglodytes, even the youngest can have a meaningful number of hit points.

Wealth is determined by consulting the treasure table.

Bugbears or Cavewights encountered at this level are recluses. Double the widths and heights of all passages. Results that may have indicated a guardroom, portcullis or reinforced doors are discarded if this result occurs; replace with a roughly dug-out stone cave with a 25-foot diameter. Present are piled furs serving as a bed, a large block for sitting and a barrel or found crate used for holding roots, fruits and chunks of rotting meat. Adjacent to these provisions, add a pile of bones beside a stinking heap of garbage. The bugbear may be absent 20% of the time. Additionally, there is a 10% chance that a crude wooden cage or pen contains 0-3 human captives. Dungeon ends, unless a 10% chance permits an opening leading to an alternate dungeon wing.

Dwarves will give quarter to intruders before engaging in combat and are willing to trade goods, especially mineral ores for food or iron tools; see bartering. Every sixth dwarf is a levelled cleric (1-5), fighter (6-17) or thief (18-20). Clerics use godentags; thieves, a short sword.

Elves will give quarter to intruders before engaging in combat but are bound to be standoffish even to other elves or half-elves. With a charisma check made by the character with the highest number, they're willing to provide details and guidance regarding the lands within 40 miles. Every fifth elf is a levelled cleric (1-4), fighter (5-13), mage (14-17), ranger (18) or thief (19-20). Clerics use quarterstaves; mages, a dagger; thieves, a short sword.

Gnolls are few in number; if there is but one, that warrior will hold his or her ground and not seek to raise an alarm. Any dependents who are capable of fighting will come when called, although they lack training and have a morale of 9.

Gnomes will give quarter to intruders, especially other gnomes, anxiously seeking news from the outside,