Trion says World of Warcraft hasn't changed enough.
Rift developer Will Cook has stated the studio would "love to take credit" for World of Warcraft's reported loss of subscribers over the last few months.
"Well a lot of people said no game would kill WoW, WoW would sort of kill itself. And while I know we’d love to take credit for it, and I don't know, I mean it's almost shameful that this giant launch window that we have, nobody is releasing anything," said Cook.
He added: "A lot of luck has come our way but I don't think we're sitting idle. We have worked really, really hard to keep the momentum, to keep people playing, and we have a lot of plans for where we will take the game."
This comes in response to last May's news that the number of subscribers to Blizzard's supremely successful MMORPG had dropped from 12 million to 11.4 million.
Cook went on to describe the current state of WoW as "samey", saying: "It seems like WoW is these days...not lacklustre...but it feels like everybody was worried Cataclysm was going to change too much. And the feeling I got was that it didn’t change enough. It is the samey kind of thing.
"It's phenomenal, the phasing is great, it's essentially the same game it was six years ago in a lot of ways. But it's not different enough and most people I know are sort of fading from it. It's still the raiding game and social game that kept me in it for so long, kept me re-upping, but people seem to be fading from that."
Earlier this month Rift was said to be closing in on a sell-through of 1 million units.
Trion Worlds' David Reid has previously suggested that Rift is the reason for World of Warcraft's dip in subscribers after saying "It was a pleasure to see that in the latest Activision Blizzard earnings call, they inquired about Rift when Blizzard announced that their subscriber numbers went from 12 million to 11.4 million. You can do some math... we know very well where those 600,000 people are."