To play with 2 players, a third territory card needs to be added to the game. This is called the Lost Kingdom. Randomly place one of the unused territory cards in the middle of the table and populate each region with a meeple from an unused color. These are considered neutral meeples.
During play, the players have the option of invading the Lost Kingdom. To do so, a player must start a war with a neutral meeple. To win the war, the player must pay a war cost at least equal to or higher than to the current number of neutral meeples in play. By doing so, the player takes control of the region and removes the neutral meeple. The player should place the neutral meeple in their area, out of play, as it is worth 1 VP at the end of the game. You cannot start a war with a neutral meeple if you cannot pay the required war cost.
Players cannot form an alliance in a 2 player game.
At the end of the game, players gain 1 additional VP for each region they occupy in the Lost Kingdom, plus 1 VP for each neutral meeple they captured.