The update will revamp the game's PvP, adding Safehouse and Headquarters battles for four-on-four and eight-on-eight skirmishes respectively.
Sony Online Entertainment also confirmed that the add-on will introduce new weapons and additional playable characters to the Legends PvP in the shape of Green Lantern Kilowog and Sinestro Corps member Amon Sur.
"We created this DLC purely for the players that like to take the fight to each other in DCUO's amazing PvP combat," said creative director Jens Andersen.
"Our community has continuously asked for more multiplayer action in DCUO, and we wanted to deliver content that fully meets their expectations and pushes PvP to another level.
"The 'Last Laugh' is the first DLC that we've created that focuses almost entirely on player versus player battles, and it adds an exciting new element as some of DC's greatest heroes and villains join to fight alongside you.
"Players will have even more opportunities to prove to the world whether heroes or villains will be triumphant."
'The Joker's Last Laugh' DLC will be available for free to DC Universe Online Legendary members in June. PC and PlayStation 3 users can sign up for the premium service for £9.99 a month.
> Read Digital Spy's review of 'DC Universe Online'
Watch a trailer for DC Universe Online below: