This room is an excellent motivator to move through an area quickly. Whether as a single room in conjunction with a puzzle or combat arena, or as a hub room providing stakes to the whole dungeon, this room acts as an organic ticking clock. When the adventurers enter this room, it begins to fill with a substance relative to the dungeon's theming. For less deadly options, it could fill with sand or water, both opening up traversal options as they rise, providing a double use for the mechanic. For a more dangerous option, the room could fill with poisonous creatures or a deadly gas. Either way, consider the length of the encounter or dungeon and time this threat accordingly so that your players can make their way through enough of the encounter while also having no time to slow down.