It turned out that the maze is generated in a sequence. The game needs to decide, as it draws each new square of the maze, whether it should draw a wall or a space for the game characters to move around in. Each square should therefore be “wall” or “no wall” – “1” or “0” in computer bits. The game’s algorithm decides this automatically by analysing a section of the maze. It uses a five-square tile that looks a little like a Tetris piece. This tile determines the nature of the next square in each row.