3. Mossy cave
Read-aloud text
You find yourself at an opening into the right side of a long chamber. The ceiling rises roughly 20' overhead, and the floor slopes steeply to about 25' below before leveling off. The walls appear to be discolored in red and green hues.
Movement
Whenever someone walks/runs on the slope (approximately the first 20' into the room), it should trigger a balance check.
Unless the players have spotted the rubble (see "Other" below) or are otherwise taking precautions, the players should not be told about the poor footing until someone moves in and triggers the balance check.
The balance DC is 7 for the first (surprised) victim, who is likely moving at normal speed with the expectation that it's normal ground. After that, the DC is 2 for anyone aware of the rubble and willing to move at half speed. Again, this DC probably
appears to be very low, but anyone in heavy armor will likely have penalties so severe that failure is a real possibility. In addition, since a check is needed with each move action, and since it likely requires 2 move actions (at half speed) to get down to the level ground, there are 2 chances for failure. Falling at any point will cause the PC to slide down to the level ground. Assign 1d3 damage if they fall/slide from the upper half to the bottom. Assign no damage if they fall/slide from the lower half to the bottom. Regardless of where they started their fall, they end up prone at the bottom and have the usual penalties for being prone until they stand up.
The level floor requires no balance checks, but it is also full of loose debris. I would treat it as difficult terrain.
Other
- listen for bats & spot for guano = same as area 1 (technically, being closer to the bats, it should be easier to hear them, but we're counting on the heavy moss to muffle the sound a little bit, thus maintaining the original DC)
- spot DC to notice floor is unstable due to loose rock/rubble: 10
- spot DC to determine that the red & green discolorations are actually moss: 10
- knowledge (nature) DC to determine that the moss is harmless: DC 12
- humidity check: as per module
- spot DC to notice abnormally large amounts of bat skeletons while in the room/chamber: 12
- spot DC to notice abnormally large amounts of bat skeletons once the PC is up in the initial flat part of the area 4 tunnel: 7
- listen DC, once the PC is up in the initial flat part of the area 4 tunnel, to notice that the sound of twigs breaking underfoot are actually bones: 12
- use rope DC to secure rope for rappelling: as per room 1
- use rope DC to hurl a grappling hook up and catch it on an outcropping of rock: 10 +2 per 10' of distance
- climb DC to scale the wall leading to area 4 (assumes free climbing, as no rope has been tied yet): 15
- climb DC to ascend the wall leading to area 4 using a normal rope: 10 (wall actually inverts, making it more difficult than area 1)
- climb DC to ascend the wall leading to area 4 using a knotted rope: 5 (inverted wall = hard, but knots make the climb easier)
Note that for the last 3 climb checks listed, the checks must happen multiple times (once per move action). For a person with a move speed of 30' normally, make 5 checks. For a person with a move speed of 20' normally, make 8 checks. Don't forget that failing the climb check by 4 or less doesn't mean a fall; it just means no progress. Taking 10 on this climb should be possible; taking 20 should
not be possible.
Monster
I used the Shrieker & Violet Fungus as a base, then tweaked the stats based upon size & the module description.
Vampire Moss
Large Plant
Hit Dice: 3d8+9 (22 hp)
Init: -1
Speed: 10 ft. (2 squares)
AC: 14 (-1 size, -1 Dex, +6 natural),
FF 14,
Touch 8
Base Atk: +2
Grp +11
Attack: +7 melee (attach)
Full Attack: +7 melee (attach)
Space: 10 ft.
Reach 5 ft.
Special Atk: Attach, blood drain, poison
Special Qualities: Blindsight, swarm shape, plant traits
Fort +6
Ref +0
Will +1
Abilities: Str 20, Dex 8, Con 17, Int -, Wis 9, Cha 3
Skills: -
Feats: -
Environment: Underground
Organization: Solitary or patch (2-4)
CR: 4
Treasure: None (though it's victims would leave behind treasure as per their own monster entries)
Alignment: Always neutral
Advancement: 4-9 HD (Huge)
Attach (Ex): If it hits with a normal melee attack, it inflicts no initial damage, but moves into the square of the victim and engulfs the victim in its red vegetation. The opponent is in the entangled state, similar to the Entangle spell. The opponent needs to use a full-round action to attempt a DC 20 strength check or DC 20 Escape Artist check to break free and move at half normal speed until out of the vampire moss.
Note that large size vampire moss can occupy any 4 contiguous squares (see swarm shape), and may attack additional opponents on subsequent rounds. So long as it maintains a contiguous shape that includes the square of its victim(s), it does not have to give up anyone already entangled. Thus it is possible for vampire moss to engulf one medium creature during one round, and on the next round maintain the entanglement on the initial victim while engulfing a new opponent.
Blood Drain (Ex): Vampire moss drains blood, dealing 1d4 points of constitution damage in any round when it begins its turn attached to a victim. Once it has dealt 12 points of constitution damage (total, not per victim), it detaches and moves away to digest the meal. If the victim dies before 12 points of constitution damage can be accrued, it detaches and seeks a new target.
Poison (Ex): Vampire moss injects a powerful agent, dealing a DC 13 fortitude saving throw to any victim that experiences blood drain. (Victims need only make 1 saving throw; it does not repeat on subsequent rounds.) If the saving throw fails, the victim will enter a "maddened" state, using any weapon in hand to attack random targets within reach (other than the vampire moss). If a victim enters this state, he or she cannot do anything but attack and take attacks of opportunity from where he or she stands.
The secondary damage is automatically saved, ending the effect.
Swarm shape (Ex): Although it is not a swarm and does not typically have the traits of a swarm, vampire moss does have the ability to move in a fashion similar to a swarm. That is, unlike other creatures with a 10-foot space, vampire moss is shapeable. It can occupy any 4 contiguous squares.
Plant traits (Ex): As per the Monster Manual, with one exception (see Blindsight, below).
Blindsight (Ex): Although it has the plant type and gains the traits of the plant type as listed in the Monster Manual, this creature has no ability to see visually, and thus it does not gain low-light vision. Instead it gains Blindsight, as per the Monster Manual.