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It looks like [c]SpecialDropAction[/c] is only used by monster drops (e.g. [url=https://zdoom.org/wiki/A_DropItem][c]A_DropItem[/c][/url]).

That's not what this function is for. What it does is to execute a special action that happens instead of dropping the item.

	Override Inventory CreateTossable(int amt){
		console.printf("A");
		Return null; //Don't drop anything
	}

To me it looks like the function is bugged, perhaps report it to the devs.
In the meantime you can override CreateTossable instead:
[code=php] Override Inventory CreateTossable(int amt){
console.printf("A");
Return null; //Don't drop anything
}[/code]

class invTest : inventory
{
    default{+inventory.invbar;inventory.icon "UNKNA0";}
    states{spawn: UNKN A -1; stop;}

    override bool SpecialDropAction (Actor dropper)
    {
        console.printf(level.time..": "..GetCharacterName()..": Dropped");
        return true;
    }
}

I want an inventry item to catch a drop call but not actually drop (it's a master that can't be dropped but when dropped it will drop a child item)
I thought SpecialDropAction would do that, but it never fires:
[code]
class invTest : inventory
{
default{+inventory.invbar;inventory.icon "UNKNA0";}
states{spawn: UNKN A -1; stop;}

override bool SpecialDropAction (Actor dropper)
{
console.printf(level.time..": "..GetCharacterName()..": Dropped");
return true;
}
}
[/code]
Do I need to turn on a flag somewhere to get that to work or what? Or is there another way to do what I want?