The way to get rid of decadence is fighting in holy wars (both offensive and defensive), participating in Jihads or fighting against Crusades. The higher a decadence you have, the worse your troops will fight and the less your demesnes will produce.
Muslim dynasties also have a decadence score - in larger realms especially, or for characters with the 'decadent' trait. Also, your wives appear to attempt to murder you with sex quite frequently. These wives might not be too fond of each other, and you sometimes have to stop them from assassinating each other (when it suits your Machiavellian purposes, of course). For instance, as a Muslim ruler, you're allowed up to four wives. While the game play is fairly similar to what you see as a Christian lord, there are a number of differences. While the game play is fairly similar to what you see as a Sword of Islam is the 'play as a Muslim dynasty' DLC pack for Crusader Kings 2. Sword of Islam is the 'play as a Muslim dynasty' DLC pack for Crusader Kings 2.
