Well, there's a good chance that they were used for divination, occasionally, why not? People have always divined, but we don't really know enough about the use of cards in that way prior to the 18th c. There's no evidence to prove it (as far as I know). So I could have ticked 3 out of the 4 boxes.
I voted that I don't know enough about the subject to say. But it seems to me that throughout history every culture has engaged in some form of divination or other, so it wouldn't surprise me if it was used for divination earlier.
So many things were used for divination - there is a page-long list in a book I have about the history of Russian magic, and it covers everything from the way a door creaks to the way a piece of metal melts - that it seems likely that cards would have been used, even in a limited way, almost as soon as they came into common use.
However, I voted that I'm not sure, because the earliest definite references do seem to be to the 18th century. As I mentioned once before here, I found an interesting reference a couple of years back that implied that divination with cards was associated with courtesans and brothels, at least in France. I'd love to know more about how that came about. It's interesting at Colette, writing in the early 20th century, still implies this connection.
Edited to add. Well, having read the later posts on this thread, I would now say that there is clear evidence that cards were used for divination earlier than the 18th century.
I voted yes. Paul Huson, in his book "Mystical Origins of the Tarot," makes a good case for card divination being practiced prior to the 18 Century. He mentions a 14th Century literary allusion to the practice of cartomancy in a Spanish epic poem titled "Spagna Istoriata." He also mentions a 15th Century German oracle book titled "Ein Loszbuch ausz der Karten gemacht" that was intended to be used with a deck of playing cards. These oracle books were apparently very popular during the 15 Century. Although Huson admits that there is no direct evidence that Tarot decks were used this way, I cannot imagine that divination would be practiced exclusively with playing cards and never with Tarot.
I do believe that divination would have been an incidental use of Tarot prior to the 18th Century. Tarot was primarily used for playing card games until divination with Tarot was popularized by 18th Century occultists.
*Edited to add title of Huson's book. I forgot to include it.
Even if we do not have much evidence regarding a sub-culture of card diviners prior to the 18th Century, we can marshal a great deal of evidence for other forms of divination for quite a ways prior to that.
Everybody wants to know something, and everybody seems to feel that the Universe has an obligation, desire, ability to spell it out for them.
Somebody, prior to the 18th Century, picked up a pack of cards and somebody told their fortune with them, or at least tried to.
Cards are a lot less messy than the entrails of a lamb, and a lot more handy, especially in the off season!
PS Mary, I can't wait to see what you are going to do with all this data.
If our cave ancestors could take a piece of animal skin and make a once living animal into dinner, neddles, thread, sewing gut, etc and who could preserve meat and veggies, after praying for them to offer what ever animal brother they were hunting to give up willingly its life for the survival of the People. People that charted the skies and made up stories about what they saw. I am sure they could figure out how to entain and feed themself during the long boring winter. If they could paint on walls, and their wearing apparl without the help of stencls, computers and rulers, things they saw in nature or their minds, the clouds, etc, why wouldn't they be capable of putting them on small pieces of left over tanned hides?
Imagine AIOs distant ancestors and the rest of the willing creative people of this thread ancestors "The A. Nonny Mouse Promotional Tarot Deck Parts I, II & III", living in that time. (I just realized that I am writting a plot for a Jean M. AUEL novel.)
Be at Peace, and have a very peaceful and pleasurable night.