exploiting Environment - change terrain type at... to use large amounts of tiles

i know there is a limit of 13 texture spaces in custom tilesets, but I've observed that when using the trigger


using a terrain type that's not in your tileset will sometimes work.

Sometimes it will work, and sometimes it will give you some other terrain type.

So, does anyone know how to successfully exploit this?

It always work, but there's a limit on the number of tiles you can use during a game.

You could also just dig up WEU and add more tiles. :P