TIGRIS and EUPHRATES rules summary
By Nikolas Lloyd 2005

Preparation: each player takes a screen, two catastrophe tiles, four leader discs, and six development tiles from the bag.  On the board, each griffin is covered by a temple tile with a treasure (undyed cube) on it.  One player is chosen to start.
In his turn a player makes two actions, each of which can be any of: position a leader (placing him on the board or moving him from square to square); placing down a tile (catastrophe or development); swapping up to 6 tiles (those discarded are out of the game, face down). At the end of his turn a player earns Victory Points (VPs) from his monuments, and all players replenish to 6 tiles, 
A kingdom is made up of orthogonally joined pieces, one of which must be a leader.
Placing a leader: must be on to an empty space next to a temple tile, never on a river, and never such that they join two kingdoms.  If later all temples next to a leader are removed or changed into a monument, the leader must be removed.
Placing a tile: farming tiles must be placed on empty river spaces, and other development tiles must be placed on empty dry land.  Placing a development tile earns 1 VP of the tile’s colour, for the dynasty with the leader of the appropriate colour in that kingdom, or, if there is no leader of that colour, to the dynasty whose king (black) is in that kingdom (N.B. kings do not get VPs from non-black monuments).  No VP is earned for a tile that joins two kingdoms.
Catastrophe tiles can be placed only on an empty space or on top of a treasure-free tile; never on leaders, nor monuments, nor treasures.
Conflicts: There are two kinds.
•	A leader can be placed in a kingdom with a rival leader of the same colour.  In this case, the attacker counts the number of temples his leader is next to, and adds to this temple tiles from behind his screen.  The defender then does the same and must equal the attacker’s total to win.  The loser’s leader is removed, the winner gains a red victory point, and the temples used off-board are discarded.
•	When two (never three or four) kingdoms containing leaders of the same colour are joined by a tile, no VP is earned for the joining tile, which is covered by the Unification Tile (handshake).  The attacker declares which leader will attack first and counts all the tiles of that leader’s type in his original kingdom, and adds to the total tiles from behind his screen of the same colour.  The defender does the same and must match the attacker’s total to win.  The loser’s leader is removed as well as all tiles in his original kingdom of that colour (Exception: if priests compete, temples with treasures and temples next to leaders are left in place), and the winner gains one VP of the same colour for each removed piece. If this splits the kingdoms, conflict ends and the Unification Tile is removed, otherwise, the attacker declares which next leader will compete with his rival. 
English variant: in conflicts, attackers may only add tiles that give them a chance of winning, and defenders can only match, never over-match the attackers score, to prevent players from abusing the opportunity to discard tiles.
Monuments: When an active player places the fourth of four tiles of the same type in a 2x2 square, he may (as long as no conflict remains unresolved) then turn all four tiles upside down and add a monument, which has the same colour in it, on top.  If he does not do this immediately, there is no second opportunity to build a monument on that spot.  Monuments are never removed, and there are only six of them available.  Monuments are part of kingdoms, but do not count as supporters in conflicts, nor temples sustaining leaders.  Unclaimed treasures are left on monument tiles.  Monuments earn 1 VP in each colour for any leaders of those colours in a kingdom, at the end of an active turn.  Kings (black) claim VPs from black temples only.
Treasures: When at the end of a turn a kingdom contains more than one treasure, the player with that kingdom’s  trader (green) may claim all but one of the treasures.  If one treasure is one of the four corner treasures, that one must be chosen.
Game end: occurs when (a) a player cannot replenish from the bag to a hand of six tiles, or (b) only 1 or 2 treasures remain on the board.  The winner is the player with the most points in his weakest colour.  Treasures count as any colour.  Ties are split by comparing second-weakest colour, then third, then fourth.