Bukkit

Dynamic difficulty is a feature that gradually makes the game harder as a lease ages. This happens in two ways. The first is increasing the game difficulty every third of the lease; starting from easy, then going to normal, and finally hard. For a 72 hour lease this means one day of easy, one day of normal, and one day of hard. Additionally the plugin gradually increases the monster spawn limit and decreases the animal spawn limit.

At the start of the lease the monster spawn limit is about a third of the server's settings. As the lease ages, it ramps up to the limit defined in the server's bukkit.yml. The animal spawn limit, unlike the monster spawn limit, decreases as time goes on. Making animals more scarce as the lease ages (note this does not affect water animals).

How to Disable Dynamic Difficulty

To disable the dynamic difficulty feature simply open the config.yml and set dynamicDifficulty to false. This will disable the feature.