Ant Tunnel Exploration System

May 28, 2011

The following is an abbreviated version of the Ant Tunnel Exploration System found in the Fire in the Jungle Supplement.  It can also be used for adventuring in any complex or unmappable subterranean location, while still retaining the essential tension of dungeoneering:  Go deeper or go home?

Previously, I wrote about the ant tunnels beneath The Jungle, including a method for randomly generating ant tunnel geomorphs.  The complex structure of the ant tunnels makes them a challenge to explore and nearly impossible to map.  A delve into the tunnels can be played without reference to any map or visual representation of the convoluted tunnels by using the Ant Tunnel Exploration System.  The complexity of the tunnels and how it might affect adventurers is abstracted into the system.

Depth:  The Depth factor reflects the increased risk and reward of exploring deeper into the tunnels.  It is used in the following way:
• Depth starts at zero when the tunnels are first entered, and cannot go below zero or above 10.
• Add the Depth factor as a bonus to the Tunnel Event Roll.
• After each Tunnel Event: The Depth factor increases by one if the party wants to continue going further into the tunnels. The Depth value decreases by one if the party has chosen to turn back towards the surface.

Lost:  It can be assumed that explorers are using a method of tracking their path (mapping, wall marks, trailing twine, etc.), but tunnel events can disrupt those methods and cause the explorers to become Lost.  When Lost, instead of automatically increasing or decreasing Depth after each Tunnel Event, a d6 is rolled:
• If PCs are trying to get out of tunnels:  On 1-4, -1 Depth. On 5-6, +1 Depth.
• If PCs are trying to go deeper into tunnels:  On 1-4, +1 Depth. On 5-6, -1 Depth.

Tunnel Event Roll
Each turn roll 2d6.  If Snake Eyes (double 1’s) is rolled, then Double Trouble has occurred and no further calculations are made.   If a different double is rolled, note the total, roll again, and add the results. Continue rolling and cumulating until non-doubles are rolled. The following bonus and penalty applies to all Tunnel Event Rolls that aren’t Double Trouble:
• Add current Depth.
• Subtract the number of PCs in delving group.
The result is the Tunnel Event Roll Sum.

(Fun Fact:  I had originally designed this exploration system for use in a Tunnels & Trolls campaign, hence the resemblance of the Tunnel Event Roll cumulative rolling mechanic to the Saving Roll mechanic in T&T.)

Tunnel Event Roll Sum: Event
Snake Eyes: Double Trouble
<10: Trouble
10-14: Curiosity
15-19: Regular Chamber (4 in 6 chance of Trouble and a 2 in 6 chance of treasure. )
20+: Special Chamber

Double Trouble:  Roll twice on the Trouble table.  If Monster (1-74) is rolled twice, the party is ambushed by one group of monsters. If Hazard (75-100) is rolled twice, then a trap is encountered but no save is allowed. If a Monster and a Hazard is rolled, then this encounter involves a monster cleverly using the hazard to its advantage before or during combat.

Trouble d100 (# encountered)
1-10 Giant Jack Ants (d6 + Depth)
11-20 Giant Fire Ants (d6 + Depth)
21-30 Giant Centipedes (d6 + Depth)
31-40 Tunnel Rats (d6 + Depth)
41-50 Gobblers (d6 + Depth)
51-54 Crater Spawn (1)
55-58 Giant Daddy Longlegs (1)
59-62 Straggler (1)
63-66 Spiny Spider (1)
67-70 Giant Dung Beetle (1)
71-74 Great Golden Cobra (1)
75-79 Punji Plant
80-84 Throat Roots
85-89 Big Man’s Dilemma. This tunnel is mysteriously thinner than what it appeared a few seconds ago and now the victim is stuck. Any struggle pinches the tunnel tighter.
90-94 Enchanted Snake.  A glowing snake launches from a small hole in the wall, striking with poisonous fangs. Seconds later the snake crumbles to dust. Victim save vs. poison, or die.
95 Tunnels rearrange behind party.  PCs become Lost.
96 Tunnel collapses immediately behind party (+1 Depth, Lost).
97 Air sucked out. Light source extinguished. Lost. Party must immediately choose whether to backtrack or rush ahead. If backtrack, -1 Depth. If rush ahead, any Trouble next turn is Double Trouble.
98 Indigestion.  Fast rising water ejects delvers out of tunnel, Lost, -d6 Depth, Light source extinguished.  Water recedes quickly.
99 Flush of water. +2 Depth, Lost, Light source extinguished.
100 Roll 2d6: Snake Eyes = Earthquake! Tunnel collapse immediately behind party (+1 Depth, Lost) and on top of party (Xd6 damage where X = Depth/2, Light source extinguished).

Light source extinguished: Some tunnel events cause light sources to extinguish. If the PCs cannot see, any movement causes them to become Lost and any encounter is Double Trouble.

Curiosity d6
1 Odd odor or startling silence
2 A pile of poo or puddle of pee
3 Smashed skulls or broken bones
4 Strange sound or troubling tremor
5 Crumpled armor or corroded weapon
6 Something dead or something bled

Special Chambers are encounter areas with features, monsters, and treasure according to the judge’s designs.  Roll on the chart to determine which Special Chamber is found.  The following is an example of a Special Chambers chart, representing a colony of Giant Fire Ants:

Special Chambers (Giant Fire Ant Colony) d6
(Die roll)x10% chance of Ant encounter each turn.
1 Blaze Furnace.  The fire ants gather massive amounts of (mostly) combustibles in these chambers and move about in frenzy to create an intense inferno.  Secretions of the fire ants fuel a heat so great that the walls of the chamber become glass.
2 Ash Brood.  As the furnaces cool, eggs are moved into the chamber to incubate in the warm ashes.
3 Junk Vault.  The fire ants fear things that don’t melt in the furnace chambers.  They view such items as threats and dispose of them in chambers like this one.  Precious gems and metals and magic items can be found amongst the piles of blackened iron.  These chambers are always sealed with thick glass doors.
4-6 Glass City.  The soil is excavated from around the glass chambers and tunnels, creating a massive alien city of glass. A maddening hum fills the city, caused by the fire ants climbing and rubbing against the glass.
Queen’s Chamber.  Only found if a 6 is rolled while in the Glass City. A twisted glass temple where drones attend to the Queen. After a drone mates, the Queen immolates him in a purple flame and consumes the remains.

Giant Fire Ants are slightly smaller than their non-fired kin. They are fireproof and secrete a combustible chemical through their exoskeleton.  A single fire ant only produces a brief flash of flame, but a well-used trail often burns robustly.  During combat, the secretions increase and the ants will swarm and immolate the enemy in flame.  It takes a full round for the inferno to form. Anybody caught in the fire takes Xd6 damage per round, where X = the # of ants that contributed to the blaze the previous round.


2 Responses to “Ant Tunnel Exploration System”

  1. […] assortment of lairs to be found in the Ant Tunnels, or […]

  2. […] thing in the Fire in the Jungle supplement that I’d like to revisit or change, it’s the Ant Tunnel System. My original intention of that system was as an extension of the Jungle Event System…the […]

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