All magical doors radiate a dweomer (The magical aura on an enchanted item; or more broadly, the aura of a magic spell having been cast while active); they may be of wood, metal, or stone, and always have heavy preservative magics laid upon them. These preserve the materials of the door and frame and make them resistant to shattering when struck. These magical powers on doors as follows.
Unless a one-word password is spoken by someone touching this type of door within 2 rounds before opening it, it will cast a 10 feet radius Hold Monster (60% chance) or Sleep (40%) on any creatures standing before it or passing through it. Some of these doors cast only one or the other spell, not both, and in all cases the spells are cast as though by a 12th-level magic-user (if save throw is an option).
Any creature(s) passing through this type of door are instantly Gated to a specific or random destination (typically: 01-36%) elsewhere in the realms/world, usually deep in the mountains or glacial wastes; 37-60%, Astral Plane; 61-82%, Ethereal Plane; 83-92%, Nirvana; 93-98%, the Nine Hells; 99-00% Limbo or another specific chosen plane, usually the Abyss or a parallel Prime Material Plane), such gating occurring all of the time, or at a specific trigger, or some of the time randomly or at a set rate (i.e., every seventh time the door is opened).
This door bears a permanent symbol (see the 8th-level wizard spell and 7th-level cleric spell) graven upon it, usually covered by a sliding overlay panel, which moves aside to reveal the symbol whenever a living creature approaches within 10 feet of the “outward” or “active” side of the door. (Too much casting of permanency spells is said to have aged the user of magic prematurely.)
Every third time this type of door is opened and closed, it upon closing casts a Silence 150 feet radius upon the back(s) of any creature(s) who have passed through it, the central focus of this spell being 150 feet from the frame of the door.
This type of door temporarily negates the powers of magical items borne through it like a Dispel Magic spell. Artifacts are unaffected, but all magic items except scrolls and other written magic (maps, spell books, etc.) must save vs. spell or be negated, all powers nullified, for a period of up to 20 minutes. Characters’ spell-casting abilities and memorized spells are unaffected.
Dead creatures (including characters) who fall or are carried through this type of door are temporarily animated (as in an Animate Dead spell), such animation lasting for 1d12 rounds. Such creatures may be turned, “dispelled” (which will cause them to become simply inanimate corpses again), or controlled by Summon Undead spell; otherwise, such creatures will attack any living creatures within 70 feet, as zombies or monster zombies (depending upon the nature of the dead creature).
Any creature passing through this type of door (or sometimes, every second or third creature passing through) must save against spell or be blinded and feeble-minded for 1d6+1 rounds. At the end of this time, affected victims must save again, at +2; if this save is failed, they remain feebleminded, or blinded, or both (DM’s choice) for a further 1d6+1 rounds.
With this door, any creature (or at DM’s option, who are chosen at random, or fail save vs spell) passing through this type of door will receive an extremely clear and vivid mental image of a scene with action, characters and background, being, or item, of up to 12 seconds duration, chosen by the creator caster of the door.
This type of door is metal, and locked; if picked or forced, it electrifies (dealing a 4d6 lightning-like discharge that conducts through all metal). It can generate an unlimited number of such discharges, emitting one each time the door is forcibly opened. Nothing will happen if the door is unlocked by a key or password, and if the door is opened and remains open, only one initial discharge is produced, and another will not occur until the door is closed
(whereupon it instantly locks) and is forced open again.
This type of door is beautiful and adorned with a beast-head knocker or doorknob; if its lock is picked, or the jeweled
(usually embedded with rubies, emeralds, or amber stones) eyes of the beast-head are disturbed, the doorway will emit monsters within 2 rounds of being thus disturbed (DM decides what monsters are summoned). If the door is closed after being disturbed, it will fly open again when the monsters are released.
The Dread Portal. This, the most infamous type of doors, contains an imprisoned Wraith encased within the door. The method of capture and imprisonment within the door was lost with it’s caster, all that is known is that anyone touching the door directly is drained of life at 2d20 damage each time (or, if they remain in contact with it for more than one round, 2d20+20 of damage per consecutive round they are touching). The wraith cannot be turned or dispelled while in the door but can be turned or dispelled if the door is shattered and it escapes (whereupon it will probably attack all living creatures nearby).
Any magical types of doors can be combined with physical traps, and most are, as follows.
Handles (or doorknobs) containing poisoned needles, or cavities with sliding covers (activated by disturbing the handle or knob) containing rot grubs, green slime, or brown or yellow mold.
Bladders of poisonous gas (or vapor laden with yellow mold spores) that will be ruptured if door panels are struck with any force.
Mechanism that fires daggers, spikes, javelins, or darts into the backs of creatures after being closed, unless deactivated with a key.
Pull-ring handle on the door pulls out, causing (by means of cables and pulleys) a sliding panel of floor in front of the door to move, plunging creatures in front of the door into a (spike-lined, water-filled) pit.
A wide doorsill, if stepped on three times (i.e. by three successive individuals) triggers a pit opening immediately beyond the door.
The entire door is hinged and weighted so as to topple downward upon anyone opening it by pulling on its pull-ring. Any-one beneath it when it falls suffers 6d6 points of crushing damage.
Well, just use your imagination and enjoy these trap doors.