You can do this by creating 6 slides each with a different die animation and a further slide with a button to run a macro. The six die slides should have on click transition OFF and a button to get back to the first slide.
Assuming the die slides are # 2 - 7
Sub chooseMe()
Dim choice As Integer
Randomize
choice = (Rnd * 6) + 1
SlideShowWindows(1).View.GotoSlide (choice + 1), msoTrue
End Sub
If you don't know
how to use a macro see here