What are the Chambers of Xeric?
After the tyrant king - Lord Xeric - was ousted from power, he fled to the sandstone mountain of Mount Quidamortem along with those still loyal to him. They built a temple atop it, which has since fallen into ruin, and used the caves within to conduct all manner of experiments, resulting in the creation of strange hybrid species, interplanar incursions, and other bizarre happenings. Most interestingly, somehow the layout of the location appears to shift - possibly some form of ancient security mechanism set in place by Xeric, or possibly just the result of some of the more outlandish experiments that were conducted.
Either way, of all the places he could've fled to, he chose here. A curious adventurer might wonder why. An opportunistic one might wonder if they could find whatever captured Xeric's attention and wield it for themself. And so explorers of all stripes find themselves at a set of grand doors, built by Xeric's chief artisan, ready to adventure through the depths.
General structure for the adventure:
An adventure through the Chambers of Xeric is split into 3 floors. The first floor consists of a Recovery Room, a Scavenger Room (labeled as "Chase Sequence" in the sidebar), and 2-3 randomly determined other rooms (under "Combat Encounters" or "Puzzles" in the sidebar) in a randomized order, with the exception that the recovery room cannot be first. The second floor is the same as the first, though with different combat encounter/puzzle rooms. None of the combat encounters or puzzles should appear multiple times within the raid. The third floor is dedicated to the final boss, the Great Olm.
In between every room, the party has 10 minutes to prepare themselves for the upcoming encounter. Relevant options for this are described in the Recovery Room page. They are limited to 10 minutes as the shifting nature of the Chambers could cause a group that stays stationary for too long to become isolated and cut off from the rest of the cave system.