list of variables you can pull from Var()

Find more here: https://github.com/stepmania/stepmania/search?q=LuaThreadVariable&unscoped_q=LuaThreadVariable

BGAnimations

File1, File2

Used for your BGAnimation, since BGAnimations accept two files as arguments.

ScreenSelectMaster (AKA metrics ActorScroller)

GameCommand

Used to get the name of ActorScroller items in metrics.

For example if you're using an ActorScroller for ScreenSelectPlayMode and one of your choices looks like this: ChoiceStandard="applydefaultoptions;name,Standard;text,Normal;playmode,regular;difficulty,easy;screen,ScreenSelectMusic;setenv,sMode,Normal"

Then if you want to show unique icons per choice with ScreenSelectPlayMode Icon, you can obtain the name field of the choice and the text field of the choice by getting the GameCommand variable and doing GetText() and GetName().

Example of it in action:

local gc = Var("GameCommand"); --Grab GameCommand variable
local text = gc:GetText() --The name field from a choice defined in metrics
local name = gc:GetName() --The text field from a choice defined in metrics

return Def.ActorFrame{
    LoadActor(name)..{};
    LoadFont("Common Normal")..{
        Text=text;
    };
}

Global

LoadingScreen

Returns the name of the current screen. Note that this is only set when the screen is being loaded, so it must be used in InitCommand or outside of any actors.

PreviousScreen

To be used in conjunction with LoadingScreen, the name of the previous screen. Same restrictions as above.