Ok start game button, add the mouse object, then add the event:
Mouse.OnObjectClicked(YourButton)
-> System.GoToLayout{YourLayout
Then for the dice, to get a random number between 1 and six use rnadom()
like this:
Global var die_value
Mouse.OnObjectClicked(Dice)
-> System.setValue(Die{int(random(1, 6))})
->