I believe this works on non expansion as well as expansion but I am not certain. This is a modifyed script created by M0ntly_Python. I cannot create scripts myself but modify them to do my perpose.
>>>gasp as units fall right through the floor<<<
Use this also to create pits like in pit of doom that can be any shape! WARNING! Anny modification of the height of the land will cause it to jump up a little and the effect won't work!
I myself are already made a few fun maps using this script so I hope you will too! I have included a large scripts to create a large map and a tidgy one too. The sizes will change according to the number of players too so launch it the number of players to suit your size. It will not destroy the effect if you change the size of the maps so don't worry abou that either.
Hope this helps you create so amazing as that will take anybody literally days to work out! I do not know anybody currently who has ever used or knows this trick so enjoy a big secret!