Transferring Items from Different Maps

[Kyle]

I think you're confused, or I am.

A key is an item, items can be carried around through whichever maps and used for whichever thing you want it to be used for. There's nothing complicated to it. Worse case, you can just use a global variable to check if the player has the item or not. I don't really know what you are trying to get out of this, but I'm sure it was answered before.