According to the wiki, the PC version of Dungeon Defenders comes with the "gameplay code and source" for UDK, for the purposes of modding.

However, it's not listed in the usual place ("Tools" in Steam), and I can't find any other info online.  Where is the source code?


Question: Do delegates defy OOP
Answer: 
  In my head, this is still quite well separated as the delegate only knows what to reference, but this by itself means it has to know about something else outside it's world!


But it doesn't. Your delegate is just a variable that when invoked calls something. If you have a string variable, it could contain anything. Your class isn't somehow breaking encapsulation if another class sets your string variable to "foobar". Likewise, your class' encapsulation is not broken if your delegate is set to "hide this UI widget when triggered".