So I've been wanting to insert the pendulous staircase for my group for a while now. I love the concept of the stairs falling apart as all sorts of mayhem goes on. I'm sticking an incorporeal monster on this staircase too, I think. There's only one small problem:
I don't really get how the staircase works. For the record, the official data for the trap is as such:
A sort of double trap, the pendulous staircase menaces those who tread too heavily upon its fragile steps, threatening to crush climbers like a gigantic pendulum, but also leaving them stranded amid whatever dungeon depth they seek to escape.
The Trap: A huge but loose length of chain supports this stairway. While it is strong enough to support the stairs and considerable additional burdens, the stairs maintain their position by relying upon fragile moorings fastened into the cylindrical well. As passersby tread upon the stairs, they potentially break these moorings, causing the stairs to sway. As the central column becomes less fixed in place, it crashes against the walls, crushing climbers or sending them careening into the depths.
How It Works: This spiral staircase consists of a central pillar in a 90-foot-deep shaft. Stone steps connect the central pillar to the walls of the shaft. These steps fit into shallow slots cut into the wall. Characters who descend the staircase to the bottom discover a gap between the last step and the floor of the lower chamber.
Among these stairs, spaced approximately 15 feet apart, are several steps deliberately designed to break. These false steps appear nearly identical to the solid steps, though a DC 25 Perception check notices the almost imperceptible cracks. A character who steps on a “breakaway stair” risks falling through the broken tread and falling down to the next twist of the spiral staircase.Once a step had broken away, any contact with the stairs sets the whole central column swinging. Each round, all characters on the steps must make a Reflex save to avoid the “pendulous staircase.” The DC of this Reflex save increases by 1 for every one of the 14 breakaway stairs that is broken. If a character fails her Reflex save, roll 1d20 and add the number of stairs broken, then reference the Pendulous Staircase Effects chart to determine how the stairs’ movement imperils the character.
Breakaway Stair CR 3
Type mechanical; Perception DC 25; Disable Device DC 25
EFFECTS
Trigger location Reset none
Effect 15-ft. fall to steps below (1d6 falling damage); DC 20 Reflex avoidsPendulous Staircase CR 10
Type mechanical; Perception DC 26; Disable Device DC 30
EFFECTS
Trigger location Reset none
Effect swinging stairs (roll 1d20 + number of broken stairs; reference swinging stairs effect chart); DC (15 + number of broken stairs) Reflex avoids; multiple targetsTable: Pendulous Staircase Effects
Steps Broken
2–4 The stairs wobble, but create no hazardous effect.
5–8 The PCs are bounced against the wall, taking 1d6 points of bludgeoning damage.
9–12 A DC 12 Acrobatics check is required to move. More steps become unstable, and 1d4 –2 breakaway stairs snap out of place.
13–16 The PCs are struck by the pillar or slammed against the wall, taking 2d6 points of bludgeoning damage.
17–20 The PCs are thrown from the stairs, taking 1d6 points of damage for every 10 feet fallen.
21–24 The PCs are struck violently by the pillar or smashed against the wall, taking 4d6 points of bludgeoning damage.
25–28 A DC 20 Acrobatics check is required to move. More steps become unstable, and 1d4 breakaway stairs snap out of place.
29–32 The PCs are clobbered by the pillar, taking 8d6 points of bludgeoning damage.
33–34 The stairs collapse. The PCs fall from the stairs, taking 1d6 points of damage for ever 10 feet fallen. In addition, falling debris causes all PCs to take 8d6 points of damage (DC 15 Reflex save for half)
What I don't get is how these effects can happen, or any of it can, really. The steps seem to be connected to both the wall and the pillar, meaning it would theoretically hold up even if stairs were missing? How can the pillar slam against someone while it's attached to stairs they're on? How can it rock at all without breaking all the stairs on that side?
While the flavor of this trap really intrigues me, I just can't wrap my head around the specifics. Which is hugely problematic for running it, really. I was hoping one/some of you could shed some light on this thing? I guess I'd also accept other, equally wacky spiral stair based traps and hazards.
What I don't get, is how the individuals steps don't stop eachother from being pushed in to any significant degree.
Assuming these steps are close together, any set of three steps(with the middle step being the one in question that is being pushed into the wall.) would always stop eachother from going all the way into the wall.
Maybe I'm overthinking it.