In Kahuna both players take on the role of tribal priests in the South Seas and they must use Kahuna magic to gain control of the island archipelago. Whilst this acts as the theme it begins and ends here. Kahuna uses a mid sized board that depicts 12 islands, all of which are individually named. Each island is connected to other islands by way of 3,4 or 5 land bridges. Like all games in the series, a deck of cards control the game play and the starting hand for each player consists of 3 cards. A further 3 cards are turned face up to act as table cards. On a player's turn they can play a card, which depicts the shape and name of one of the islands. They can then place one of their bridge markers on any of the land bridges that lead to or from the named island on the card. A player can play anywhere from 0-5 cards on their turn (if they have that many) but they will only ever draw 1 card to end their turn. This is the basic nature of the game.
In order to win both players have to control the most islands at the end of each round (there are 3 rounds in total) and doing so awards points. To control an island a player must control more than half of all the land bridges to and from any given island. When this is achieved they can place a control marker on the island AND they get to remove all the land bridge markers of their enemy that lead to or from the island. This could then result in a knock-on effect to surrounding islands - weakening their control on those islands also. It doesn't take a genius to realise that clever tactical positioning can have dire consequences for your foe. Another option open to players is to try and remove an enemy's bridge marker without controlling an island. This is possible by playing 2 island cards together. If the enemy has a land bridge marker on the connection between the two islands then it is removed. This can also occur by playing two cards from the same island. In this case any one enemy bridge marker that leads to or from the island can be removed. This is more difficult however as the deck only has 2 cards for each island. When drawing a card to end a player's turn, they can choose to take 1 of the face-up table cards or a random card from the draw pile. The current round ends when the last available card is drawn into a player's hand.
At the end of rounds 1 and 2 the player controlling the most islands scores 1 and 2 points respectively. The end of the 3rd round scores differently as the player controlling the most islands will earn a number of points equal to the difference in islands controlled. This will often be the game breaker.

Kahuna is a far more strategic game than other titles in the series and luck plays a much lesser role. For this reason Kahuna will appeal to some gamers more than others. The scoring system is designed to ensure very close games and both players will always feel they can win it in the third round. Kahuna's theme may not be as strong as other games in the series but it shouldn't be ignored, as it is a title that rewards the tactician.