Jeff Strain, co-founder of ArenaNet, gave a very interesting speech on the challenges of creating a successful MMO. Here’s an important point:

Before you start building the ultimate MMO, you should accept that “MMO” is a technology, not a game design. It still feels like many MMOs are trying to build on the fundamental designs established by UO and EQ in the late ’90s. In the heyday of Doom and Quake we all eventually realized that “3D” was a technology, distinct from the “FPS,” which was a game design. It’s time we accepted that for MMOs as well. We are finding ways to overcome many of the limitations of the technology that dictated the early MMO design, such as Internet latency and limited global scalability. These improvements can enable a new class of online games that break out of the traditional MMO mold and explore new territory. It can be a daunting proposition to willfully walk away from what seems to be a “sure thing” in game design, but lack of differentiation is probably the number one reason that MMOs fail, so we all need to leave the comfort zone and start innovating, or risk creating yet another “me too” MMO.

Also, similar to Civ4‘s development, they started an external alpha test years before release:

It’s crucial to get feedback from outside the development team at a very early stage. We started alpha testing over three years before Guild Wars was released. To say that the game was crude at that point is a bit of an understatement – I think we’re still tracking down screenshots from that period and trying to get them burned. It was a very controversial decision at the time, and generated a lot of heated debate within the development team, because it flew in the face of the traditional wisdom that you should never show anyone outside the company what you are working on until it is perfect. I wish I could tell you that every tester we brought into the alpha test was honest, abided by the NDA, and gave the development team carefully-considered and high-quality feedback after each of the tri-weekly play sessions, but that would not be the truth. There were several times after we launched the program that we revisited the notion and discussed whether the good outweighed the bad. But we kept at it, and by the time Guild Wars shipped in April, 2005 it was clear that the game had benefited from the alpha test program, and today we consider it an essential component of the development process.