Note: This information was taken from TSR's original AD&D adventure, the Temple of Elemental Evil.
For the players: This 20' wide passageway is strangely lit by some obviously magical means. In the center and the short northern extension, it pulses with a disgusting gray luminosity; to the west it glows with a green radiance; and to the east, bands of dull red light seem to float in the air. Each pair of double doors (to the north, west, and east) is a great brass construction, covered with horrible scenes and leering faces. To the south is a huge slab of bronze, a solid portcullis. A mighty windlass flanking it to the east obviously raises and lowers this barrier.

For the DM: The designs in the corridor are very similar to those in the Processional Corridors (areas 209). The windlass is secured with a chain and huge padlock, and a bar is across the gate -- unless, of course, either or both have been opened.

The central 20' square at the intersection is "safe, " but not so the corridors. Any movement out of the safe area causes the walls of the corridor entered to glow brightly, and elemental forces (see the following descriptions) are felt. For each ten feet of travel, 1-6 points of elemental damage is inflicted; each victim may make a saving throw vs. spells each time this occurs, and success indicates that no damage is taken. Note that any victim carrying or wearing the appropriate Temple symbol automatically succeeds in each of these saving throws.

East: Walls glow fiery red; the smells of sulfur, burning flesh, and hot metal assault the nostrils. Victims take heat damage.

West: Walls, floor and ceiling shed a deep green gloom. Movement is slowed to 3 " rate (as if moving underwater). A moist reek of seaweed and rotting fish pervades the air. Victims take damage as if drowning.

North: A great rush of moaning and shrieking wind strikes the party. It oddly and undescribably smells like the winds of age, war, and death. Victims take cold damage and are blown backward 30 feet; each also takes 1-6 points of impact damage when hitting the gate (unless it has been opened).