Besides the obvious fact of showcasing the 10 new figures from the Empire Strikes Back, now 31 in all, the 31 Back card served as a transition of the franchise from 20th Century Fox to LucasFilm LTD. At this point, it appears that the agreement was that anything related to the original Star Wars movie would be considered the property of 20th Century Fox while anything associated with The Empire Strikes Back would belong to LucasFilm LTD. This becomes painfully evident with the overuse of trademark symbols throughout the card. A simple title like Han Solo (Hoth Outfit) becomes a typesetting and design nightmare. By the time the 32 Backs came out, everything had been resolved to be a trademark of LucasFilm LTD.
 

 
Each figure in this assortment had its own UPC derived from the product number. Later assortments would have an assortment number and all figures would have the same UPC code related to that assortment.
 

 
After these changes, the 31 Back was a pretty basic card back. There are no offers during this release and there are only 2 versions, 31a & b. The only differences involve the toys advertised at the bottom of the card.