Players who have been following GW2 up until this point may already be familiar with the game's four primary attributes: power, vitality, precision, and toughness. But the team decided that four wasn't quite good enough, so five more attributes were thrown into the mix. While these five new attributes (three for offense, two for support) offer new and exciting ways to customize your playstyle, the catch is that players can only gain points in these attributes through trait lines or gear. Each profession also gets a profession-specific attribute. For instance, Rangers get the empathy attribute, which increases the attributes of the hunter's pet.
Traits, on the other hand, operate more like traditional MMO talent trees. Each class is given access to five different trait progression lines; each of these trait lines matches up to a pair of attributes that will be improved each time the player puts points in the corresponding tree. The trait lines also unlock major trait slots that can be filled with -- you guessed it -- a major trait to further customize the character's playstyle. But there's a lot more to the system than we can fit here, so click on through the link to the ArenaNet dev blog below and give the full blog a read.