Does teleportation require line of sight?

Question

In D&D 4e, teleportation is very common. Does it require line of sight?

Example:

An Eladrin wizard is being attacked with his back to the wall. On the other side of the wall is the room he came in from. Can he teleport through the wall to a space on the other side?

If teleportation does require line of sight, how is it different from other movement except for the following:

• It ignores terrain.
• It does not provoke attacks of opportunity.

Answer 1

From the Compendium:

• Destination Space: The destination of the teleportation must be an unoccupied space that the target can occupy without squeezing. If arriving in the destination space would cause the target to fall or if that space is hindering terrain, the target can make a saving throw. On a save, the teleportation is negated.

• Line of Sight: You must have line of sight to the destination space.

• No Line of Effect: Neither you nor the target needs line of effect to the destination space.

So, line of sight, but not line of effect. I think you mentioned the two big differences, but a teleport could go through a window, for example, or allow you to get past enemies that you could not otherwise move through/past.

Answer 2

Yes, you need Line of Sight.

One other difference from movement is that you can teleport while immobilized, restrained, or grabbed.

From the PHB3 definition of teleportation

• Destination Space: The destination of the teleportation must be an unoccupied space that the target can occupy without squeezing. If arriving in the destination space would cause the target to fall or if that space is hindering terrain, the target can make a saving throw. On a save, the teleportation is negated.
• Line of Sight: You must have line of Sight to the destination space.
• No line of Effect: Neither you nor the target needs line of effect to the destination space.

Answer 3

Teleportation does not require Line of Effect, but Line of Sight is still necessary. In your example, the Eladrin would only be able to teleport to the previous room if the wall he was backed up against had a window.

Other notable differences from normal movement are:

• Does not provoke opportunity actions.
• Unhindered by objects or terrain in the path of travel.
• You must be able to occupy the target space without squeezing.
• Can be done while immobilized or restrained, and negates these effects if you are teleporting out of the affected area.
• Can be done while prone, though it does not negate this effect.
• Unless otherwise specified, does not move a Mount and its Rider together. (Rider falls, if dismounted.)
• Teleportation speed is not affected by the Slowed condition.

The Compendium entries on "Teleportation", "Mount and Rider", "Slowed", and "Prone" cover all these points and more. The same information is also available in the Player's Handbooks.