Brickspace Dictionary: Illegal Move

Illegal Move (n.) (Ill·e·gal_Move)
An 'illegal move' is when a building techniques unnecessarily stresses the elements it consists of. This can lead to warping or breaking of the bricks if they are held in that position over time.

There are several different types of illegal moves (and legal moves, too), most of which can be found in TLG's very own Powerpoint guide . The reason for an illegal move is mostly due to the receiving brick being smaller than the one being connected to it. Sometimes, though, a connection can be illegal because of the material of the pieces: the plastic polycarbonate (PC) is sometimes used instead of the usual ABS, and a tight PC-on-PC joint can be hard to undo.

Even the much-used 'secret Lego technique' paraplating (see right) is considered as an illegal move by TLG!

The Master Builders at LEGOLAND Windsor have a tradition that, whenever a builder performs an illegal move, they must 'buy the cakes' for all the others. In the general FOL community, however, illegal moves are regularly used.