Dragon Nest update, Theater of War, is all about precisely that, giving players new combat modes and match sizes to ensure that player combat stays lively.
The new updates adds a 3v3 option to ladder matches, allowing smaller and more close-knit groups the option to take part in serious competition. There's also the addition of a free-for-all match type, with players able to take on everyone for supremacy. And then there's the new Protect Mode, challenging both sides to keep one player designated as the Captain alive while slaughtering the other side's similarly important Captain. Take a look at the trailer for the update just past the cut to give you an idea of what the modes will look like in play -- it's not new dungeons, but if you're fond of facing off against other players, it's even better.