Quoting The Timinater ! illegal connections? its completely legal! it's completely purist! oh, he fell apart SO MANY TIMES!!! I kept on knocking him off my desk! XD
No, illegal connections have nothing to do with purism, well kinda, but not really. Hooking clips to clips, minifigure parts as detail, clips to bars or rods with out a full click of fruction, stuff you wouldn't see in a LEGO set. My building style doesn't use much illegal connecting (I only do when I absolutely have to) because it stresses out the pieces.