I need some quicksand for this weekend.
Any suggestions on how to make the rules for such a hazard?
This is just quick and dirty (see what I did there?), but here ya go...
Quicksand (Hazard)
Level 4 Lurker, XP 175
Swirling sands threaten to swallow your companion for eternity!
Hazard: 3x3 squares of apparently sandy terrain are actually deadly quicksand!
Perception:
DC 17: The character notices vultures perched in the area.
DC 22: The character notices an unusual sheen on a patch of sand ahead.
Additional Skills: Nature DC 15 recognizes the general terrain as likely to have quicksand, and Nature DC 20 recognizes the exact location of the quicksand.
Initiative: +6
Trigger: The hazard rolls initiative when a creature enters one of the nine squares where the quicksand is located. If a creature would move through the central square, the hazard attacks then instead (as it takes a moment for the quicksand to liquify).
Attack
Standard Reaction, Close burst 3
Targets: Creatures in burst
Attack: +6 vs. Reflex
Hit: Immobilized
Miss: Slowed
Sustain Standard: Immobilized or begin drowning (see drowning rules in DMG). The DM is encouraged to use a dramatic sense of timing when a character trapped in quicksand begins drowning.
Countermeasures
* Athletics DC 15 to move/shift 1 square, but if you fail by 5 or more begin drowning.
* Allies come to the rescue with a spear haft or rope; required Athletics DC 15 to haul the entrapped hero 1 square. The hero must also make an Athletics DC 10 check; if the hero fails they begin drowning.