Season of Plunder is the 18th season in D2, and its launch took place on August 23rd. It introduced a few new things, some of which are yet to be released, such as:
King's Fall Fall raid
Ketchcrash (6-player activity)
Expedition (3-player activity)
Pirate Hideouts weekly mission
A new pool of seasonal weapons
New season pass
Arc 3.0
Balance changes