Lost Cities is one of the Kosmos two player games published by Rio Grande games in 1999. The game itself is wonderfully simple and can be played with a normal deck of cards, even though it would be missing a suit and the wonderful artwork.

The deck consists of 5 suits of cards each with a different color theme and artwork (backs are all the same). Each suit consists of the cards numbered 1 through 10 and three 'investment' cards. The artwork on the cards shows the progress of an expedition to a lost city, the artwork overlapping slightly on each card to provide a scene.

The story (which is not essential to the game play) is that each of the two players is an overseer for some expeditions and a race to collect as much value from the expeditions as possible.

The game begins with each player receiving 7 cards and the board (which serves as a place holder for discards) placed between them. On a turn a player must draw a card either from the deck or the discard piles and then play a card, either in his or her own stacks or as a discard.

Cards may only be played in one's own stacks on top of a card of less value and the same suit, or the empty spot corresponding to that suit. Thus the green 5 can't be played on top of the green 7. The investment cards may only be played on other investment cards or a blank spot.

Instead of playing on your own cards, it is also possible to discard a card to the middle. You cannot discard the card the same card picked up from the discard pile. There is a separate discard pile for each suit, and only the top card may be picked up.

The game ends immediately upon the last card being drawn from the draw deck. This makes it advantageous to draw from the discard piles late in the game to prolong the time you can play out your hand.

Each expedition started (even invested in) scores an initial -20 points. This means it is a very bad idea to play one only or two cards in the expedition. If the expedition contains only the cards '3 4 6 7', that stack scores 0 points ( 3 + 4 + 6 + 7 - 20 = 0). The investment cards place multipliers upon the final score. The first investment card makes it x2, the second becomes x3, and the last makes the score for that expedition x4. If only the three investment cards are played on an expedition, and no other cards, the score is -80. There is a +35 point bonus applied after the multiplier kicks in if there are seven or more cards in an expedition. Expeditions with no cards score 0 points.

Extending these rules to a normal deck of 52 cards is not difficult, though you loose one suit. Face cards are to be regarded as investment cards, while the rest of the suit is counting up. With a smaller deck but the same size suits, having such a large hand ends the game more more rapidly and thus a smaller hand might be considered.

While on the surface, the game looks very simple, there are many subtle interactions that are missed on the casual glance.

Opening
With the initial deal and the first few draws, the decision for which expeditions to develop has been made and committed to.
Middle
With the display of initial starts, avoid discarding cards that would be useful to your opponent - wait until he plays a 5 on a 2 before discarding the 4. Watch carefully which cards are picked up for signs of a quick expedition run.
End
The final cards played down must be watched carefully to make certain that the maximum points are scored. If you happen to have the cards 5-10 in your hand, but only 3 turns left in the game, the play '5 6 7' is less effective than a '8 9 10'. While this is simple to see, it gets complex across multiple suits.
General
Watch for spikes. It can be useful to score a low negative in your expedition if it means stopping your opponent. Having a 9 and 10 of one of the opponent's suits is worth playing down to get out of your hand, even at the 'cost' of -1 points up front.

By avoiding the early play of expeditions that are intended this creates difficult questions for the opponent as to which cards to discard. Bluffing plays a factor in what to play and when, but it can be dangerous to bluff too much and fail to develop your own expeditions.