Claimer: Before I begin I should note that I backed this at the Kickstarter phase, and that I am friends with the creator. I'll do what I can to not let that color my opinion.
Non-player Cards are made up of several decks of cards designed to quickly enable the creation of an NPC on the fly by drawing cards from the needed deck(s). The decks cover Traits, Professions, Relationships, Goals, Secrets, Quirks, Personalities, and Names. I'd have bought this for the last deck alone, because I suck at names, but as a combined whole these make for a great way to quickly build an NPC when the players latch onto an unplanned encounter.
This being the Kickstarter edition it came in a nice sturdy box with each deck in its own tuckbox. This ensures that you won't have a mess to deal with, which is really nice. The artwork shown on the tuckboxes (above) and the cards (below) is but a small sampling of the art for the product. Everything is by Eren Arik who uses a rough style that minimizes detail and leaves as much room as possible for the user to interpret the cards as they see fit. The cards themselves are a good quality card stock with a nice coating, they did a riffle shuffle (a.k.a. a bridge) really well right out of the box.
I decided that the best way to show these off was to take a test drive. I shuffled each deck and pulled a card and random, two for the names deck, to build an NPC from. I got a barber with unique hair color for profession and trait respectively. I decided this character would be for Numenera and so I set his hair as holographic fire, kinda like Hades' hair in the Hercules cartoon film, but in shades of yellow, red, and orange. His personality was cynical, which goes well with the phobic quirk and "knows secrets" secret card. Now I picture a man who hears a lot while doing his job, but fears revealing those secrets, to the point of being paralyzed when questioned about what he knows. His outlook on life is generally too negative (cynical) to actually do anything with what he knows anyway, so that works out in his favor. His goal is simple respect; his outlook on life an humble position make him somewhat of a ignored individual, a fact that he wishes were not true. Lastly he was once saved, by who and under what circumstance I am not sure, but it formed the basis for a strong connection to another NPC (or possibly a PC).
Overall I am quite happy with these cards. They make a tool that I very much needed for my table, and I think most GMs could probably use some, or all, of these decks as well. While the Kickstarter is long over you can buy the cards as a bundle, or in individual decks from DriveThruRPG including Print on Demand options. There is also a book format Non-Player Compendium if you are not one for cards, or just prefer to have all of your options laid bare.