The first ever Star Wars figure cardback depicted the original 12 figures, hence the name 12 Back. There were 3 original versions of the 12 Back, 12a, 12b and 12c. The differences updated the evolving “Light Saber” instructions and the name and criteria for the Action Stand offer.

For some strange reason, a version exists with a sticker depicting figures from the 20, 21, 31 and 32 Back assortments. This sticker is only known to be affixed to the 12 Back card and none of the others between 12 and 32.
 

 
Later assortments would release “refresh stickers” with current promotions to be affixed onto older stock. These stickers would create additional versions of this cardback not showcased here.