My 4e group ran into the common problem of actually having to end a session in the middle of a dungeon. Also I would not be present at the next session, and someone else was actually going to start playing with us and we needed a way to bring in the a DM PC that we have been using to fill out the party (don't worry, he is not an uberlevel locomotive). We needed an in game way to make this work and we might have to do it again. So after some thought I wrote out this magic item to help with the problem and not break the game. The gloves were made with 4e in mind but their use is so conditional that I could see them being used in games based on older rules, even stuff created by the Old School Renaissance.
Gloves of Transposition(Switchgloves) Level Any
Daily + Teleportation
These gloves look like a pair of ordinary black leather gauntlets. Each one has what looks like an obsidian jewel attached to the reverse side of the palm of the glove. Worn together the gloves are inert, they register as magical but have no ability whatsoever. The magic of the gloves only works when one glove is worn by two separate people. When worn this way the magic of the gloves enables the wearers to switch places as long as they are physically on the same plane. Each glove allows a limited telepathic link to the other user. With this link each user to do the following:
A. Open the link to the other wearer using their name.
B. Let the other user know they are ready.
C. Let the other user know they are not ready.
No other information can be sent down the link. It is not possible to don one glove and learn the name of the user with the other glove even if the other user is willing to share it.
For the magic to work several conditions must be met:
1. Each person wearing a glove must know the name of the person wearing the other glove.
2. The gloves will not allow someone to switch into immediate danger, including combat.
3. Both users must take a short rest to activate the gloves.
4. Each person wearing a glove must be willing to switch.
5. Each person wearing a glove must have communicated their readiness to switch.
When all these conditions are met a golden glow rises slowly up out of the depths of the jewel on each glove until the jewel is glowing with a very bright amber light. The users of the gloves, their clothing, equipment and everything they are touching then begin to glow until all are emmenating light, obscuring color and features. The light then begins to fade with the other user in the place of the user wearing a glove.
If the user is touching another person, then they are also transported if they are willing. Though passengers do not need to be part of the telepathic exchange that activates the gauntlets. Thus the gauntlets can switch out one for one, two for one or two for two.