Can this be used to effectively "Nightcrawler" through walls and doors or do you need line of sight? To me this is more of an invisibility trick than a teleport one. After playing this game all weekend long it is another question that came up that we couldn't find exact rulings on.

ninjaplease said:

Rulebook, page 13:

"Counting Spaces
Some abilities require players to count the spaces from a figure to the target of the ability. When counting spaces for attacks and abilities, players ignore any non-obstacle terrain in those spaces (see “Terrain” on page 18). The player just needs to verify that his target is in range for the ability to reach the target. If an ability affects figures within a specified number of spaces, line of sight is not needed unless specifically noted . However, when counting spaces for an ability, players cannot count spaces through a door because the spaces are not considered adjacent ."

Emphasis mine. Note that walls also break adjacency, although only doors are mentioned here. So no, you do not need Line of Sight unless the ability says you do, however, you cannot "teleport" through walls and (closed) doors, because the spaces on opposite sides of such things are not considered adjacent.

Cheers mate! Thank you!