Choice of profession will of course have a huge impact on how the game plays. There are eight professions in Guild Wars 2, many of which will be familiar to fans of Guild Wars, as well as a few professions new to the Guild Wars world. Each of these professions is roughly categorized by the type of armor they wear: scholars wear light armor, adventurers wear medium armor, and soldiers wear heavy armor. Currently there are three scholar professions, three adventurer professions and two soldier professions.
When designing our professions it was very important to us to make each of them feel as unique and different as possible. In addition to weapon, armor and skill choice, we've developed a number of cool profession mechanics for each one. We'll be revealing new professions on our website, so it should start becoming apparent just how much we've tried to push the unique play style of each of them.
Many players from Guild Wars are familiar with the concept of secondary professions. We included secondary professions in early versions of Guild Wars 2, but due to the unique mechanics of each profession and the increased role of race in character customization, they are no longer a feature of the game. We feel that this decision will allow us to create a more balanced game with really distinct professions that are fun to play.