Out in the wasteland, the game of choice is Caravan. Created by caravan guards using
whatever cards they could find lying around, this is a one-on-one card game played with a
cobbled together deck of loose playing cards.
Building a Deck
Caravan decks are comprised of at least 30 cards from one or more traditional playing
card sets. The deck may have any number of cards of any type, although it cannot have
duplicate cards from the same source deck. A balanced deck has a mixture of numerical
and face cards, with the specific balance tailored to the player’s personal style.
Rules
Caravan is played with players building three opposing piles (or “caravans”) of numbered
cards. The goal is to outbid your opponent’s caravan with the highest value of numbered
cards without being too light (under 21) or overburdened (over 26).
The game begins with each player taking eight cards from their deck and placing one
numerical card (or ace, valued at 1) on each caravan. Players may not discard during this
initial round.
Once both players have started their three caravans, each player may do one of the
following on their turn:
? Play one card and draw a new card from his or her deck to their hand.
? Discard one card from their hand and draw a new card from his or her deck.
? Disband one of their three caravans by removing all cards (numeric and face) from that pile.
Caravans have a direction (either ascending or descending numerically) and a suit.
The suit is determined with the first card placed on a caravan, the direction by the second.
All subsequent cards must continue the numerical direction or match the suit of the previous
card. Cards of the same numerical value cannot be played in sequence, regardless of suit.
Face cards can be attached to numeric cards in a caravan, either
Card values:
? Joker - Played against A, 2-10. Effects change based on whether it is an ace or
numbered card (see below). Multiple jokers may be played on the same card.
? Ace - Value of 1. Jokers played on aces remove all other non-face cards of the ace’s
suit from the table. E.g. a joker played on an ace of spades removes all spades
(except face cards and that card, specifically) from the table.
? 2-10 - Listed value. Jokers played on these cards remove all other cards of this
value from the table. E.g. a joker played on a 4 of hearts removes all 4’s (other than
that card, specifically) from the table.
? Jack - Played against A, 2-10. Removes that card, along with any face cards
attached to it.
? Queen - Played against A, 2-10. Reverses the current direction of the hand, changes
the current suit of the hand. Multiple queens may be played on the same card.
? King - Played against A, 2-10. Adds the value of that card again. E.g. a king played
on a 9 adds 9 to that hand. Multiple kings may be played on the same card for
multiplicative effects. E.g. 4 + king = 8. 4 + two kings = 16.
Winning
A player’s caravan is considered sold when the value of its cards is over 20 and under
27, however the other player may still outbid by increasing the value of their opposing pile
(while still staying within the 21 – 26 range). When each of the three competing caravans
has sold, the game is over. In the event that one of the three caravan values are tied
between players, the game continues until all three caravans have sold. The player with two
or more sales wins the pot.

Thanks for the responses. I think maybe my question wasn't clear. I know the rules of the game, but I was asking how I actually, physically play the game when the game screen comes up. I pressed about every key I could and nothing happened. The option for the W shortcut key (I forget what it was called) was grayed, and only "Discard" was available. I tried clicking and dragging the cards and nothing happened. I never actually had a chance to *play* a card before I just gave up.

I will try the arrow keys a bit later. But that can't be it, can it? How do I show where I want to play the cards? Do I have to cycle through every option? Is the mouse involved at all?

Thanks.