How to activate:

• Log in to Guild Wars 2 with the account where you want to unlock the item.
• Open the Black Lion Trading Company panel. The default hotkey is 'O'. You can also click the lion icon in the upper left corner of the game screen.
• Click the "Redeem Code" link in the upper left corner of the Store homepage.
• Click the "Redeem Item Code" button.
• Enter or copy and paste your gem code into the field that reads: "Enter your code".
• Click Redeem to receive your item!

This bundle includes the following: 

• Green Plush Quaggan Backpack Cover.

About the base game:

Guild Wars 2 features five different races and eight different professions, which themselves are divided into three different weight classes, you must choose from when creating your character. Unlike most other MMORPGs Guild Wars 2 doesn't feature the usual distinction between Tank, DPS and Healer. Instead every character is a jack of all trades with ten skill slots in total, five of which determined by their race, profession and equipment, one for healing and four of undefined roles that are unlocked through progression in the game, including an elite skill.