Teleporting () is possible for example in the Portal room, the Hidden Stairwell room, or with the Robes of the Phoenix Garb.
Teleporting allows you to place your hero to any revealed room in the Dungeon. This may come during your movement since it is a Free Action, and you may continue moving from your destination, if you still have speed left (and didn't teleport into a room with an enemy without Stealth).
You can teleport to the Lair Door room, but cannot teleport onto the Boss Mat. However, if you have the teleportation ability (like from Robes of the Phoenix), you are allowed to teleport away from the Boss Mat.
Note, that you can use teleportation ONLY when you would be free to move away from the room anyway. You cannot teleport if you are in the middle of combat, or have moved without Stealth into a room with an enemy in it. If you have, then you must kill the enemy first, or wait until your next turn.