Tenevar the gnome made a name for himself throughout the realms as an innovator of death and dismemberment. His mechanical and magical traps were the envy of kingdoms far and wide. High lords and monarchs called upon his services to design complex and ornate trappings and tricks to ensure that grave robbers and looters would meet a nasty end should they attempt to raid their tombs. The following trap comes from within the tome containing his journals and notes on design.
The Trapping Mirror
When the party enters the room, at the very rear of the chamber they see an ornate and beautifully designed statue holding a mirror at eye level so they may see their reflection as they approach. Once any party members gets within 30 feet of the mirror, and sees his/her reflection, the party member must make a save vs. spells, or disappear into the mirror. The party will have no idea what happened to their friend(s), or where they went. They will simply have vanished. The mirror is a Mirror of Life Trapping. In order to free the party member(s) from the mirror, it must be broken, which can be done by any conventional means. The problem, however, is getting to the mirror. Five feet directly in front of the mirror is an invisible Wall of Force cutting off the party from the mirror, which cannot be penetrated (treat as the wizard spell of the same name). It cannot be dispelled with dispel magic. Only a Disintegrate spell, or a wish can destroy it. It is possible, however, to teleport on the other side of the wall in order to break the mirror. If the mirror is broken, all creatures trapped within are released (some of them could include nasty monsters).
This trap is designed using the AD&D 2e rules, however can easily be incorporated into any RPG system.