Thebes is a game of competitive archeology. Players are archaeologists who must travel around Europe; northern Africa; and the Middle East to acquire knowledge about five ancient civilizations -- the Greeks; the Cretans; the Egyptians; the Palestinians; and the Mesopotamians -- and then must use this knowledge to excavate historical sites in the areas of these civilizations. Through the course of the game; expositions are revealed; and an archaeologist who has treasures from the requisite civilizations may claim the prize (this is a change from the first edition's handling of exhibitions). The archaeologist who learns the most about the civilizations; claims the greatest-valued artifacts; and collects the most exhibitions will win out over his or her colleagues.

The key element to the game is that it is played out over a period of two (or three) years; and each action a player performs takes a certain amount of time -- traveling is a week between cities; gathering knowledge takes time for the level of the knowledge; and actually digging at a cultural site takes time to yield a certain number of artifact tiles. The game uses a novel mechanism to keep track of this. There is a track of 52 spaces around the outside of the board. Each time a player moves and takes an action; he or she moves their player token forward in time. Players take turns based on being the one who is furthest back in time. So; a player can go to an excavation site and spend 10 weeks digging for artifacts; but that will also mean that the other players will likely be taking several actions in the interim while that player waits for the time to catch up.

In addition; the artifact tiles for each civilization are drawn from a bag that also contains dirt. When a player excavates a site; that player pulls tiles from the bag; but some may only be worthless dirt instead of valuable treasure. That dirt is then returned to the bag; making the first draw more likely to provide useful tiles.