Tigris and Euphrates is a German strategy board game designed by Reiner Knizia and published in 1997 by Hans im Glück in German (as Euphrat und Tigris) and by Mayfair Games in English. Before its publication, it was highly anticipated by German gamers hearing rumors of a "gamer's game" being designed by the respected designer. Tigris and Euphrates won first prize in the 1998 Deutscher Spiele Preis.


Theme
The game is named after the rivers Tigris and Euphrates in the region we now call the Middle-East. The rivers together formed natural borders for an area which harboured several grand ancient civilizations, including Sumer, Babylonia, and Assyria. The Greeks called this area Mesopotamia, which literally means "between the rivers".

The game is set as a clash between neighboring states at the dawn of civilization.


Gameplay
The game can be played by 2, 3 or 4 people. The play offers both tactical and strategic objectives. As with many games, the short term objectives gain prominence when more players participate, as players have less chance to follow up on previous moves. Luck plays a role, as players draw tiles from a bag, but it is seldom decisive. The game does not use dice.

The board is a map of the two rivers, marked with a square grid. There are four types of tiles with corresponding leaders: temples and priests (red), farms and farmers (blue), markets and merchants (green) and settlements and kings (black). The game starts with ten isolated temple tiles already placed on the board. Players play tiles and leaders onto the board, creating and expanding regions and kingdoms. Monuments are built on the board when four tiles of the same color are played into a square pattern.

Two leaders of the same type can not coexist in the same kingdom. Internal conflicts are caused when a player adds a second leader of a type to a kingdom. External conflicts are caused when players play tiles to merge two existing kingdoms.

During the game, players collect points in each of the four colors as a result of playing tiles, resolving conflicts and controlling monuments. After the final round each player sorts his or her points by colour. The winner is the player with the most points in their smallest category.

For example:

John has 6 black, 8 red, 12 yellow and 12 blue points; thus has a score of 6. 
Mary has 9 black, 10 red, 7 yellow and 15 blue points; thus has a score of 7. 
Kurt has 14 black, 14 red, 5 yellow and 20 blue points; thus has a score of 5. 
This is one of the novel mechanisms of the game. Players must balance their scoring and avoid overspecializing.