Blue wall
A blue wall, closer to a teal-blue hue in the MS version despite its official name, is a tile that can take on one of two indistinguishable possibilities:
- Fake blue walls, which act as dirt: Chip will turn it into floor when he attempts to step through it, but while it exists, Chip cannot push blocks over them and monsters cannot pass them.
- Real blue walls, which turn gray when Chip pushes on them, identifying them as walls.
The only way to find out whether a blue wall is fake or real in Chip's Challenge 1 is to attempt to step through it. In Chip's Challenge 2, a variant of block slapping exists that allows the player to check if a blue wall is real or fake without walking past it. Yet another method exclusive to CC2 is the secret eye, which distinguishes fake blue walls from real ones using the graphic of a fake blue wall from the in-game level editor. Of course, one can also simply view a map of the level or open it in an editor; most editors use a more grayish-blue color for real blue walls and a teal square with a white outline for fake ones.