Challenges
Challenges are an epic allegiance based system, where the three main allegiances of Reaper/Exile and Society go head to head against each other to complete a challenge.

The challenge system is ladder based, with each successful main challenge completed advancing your allegiance up the ladder, however the challenge system is split into two different challenges the "main" challenge and a "sub" or "deciding" challenge, basically there is a deciding challenge with the winner of that challenge then getting control of the next "main" challenge, when the next main challenge is completed or countered the next challenge will be a deciding challenge to decide which allegiance gets control for the next challenge etc ....

With a main challenge the allegiance in control has a specific task to complete, while the other two challenges work towards stopping them by countering their challenge, if the challenge is countered then the allegiance in control loses that challenge and does not advance up the ladder, otherwise if the allegiance successfully completes the challenge they earn a unique reward and move up the ladder.

There are a fixed amount of challenges and while they are different to each side once one side completes all main challenges they will dramatically change the future of the game with the story line and future events focusing on this allegiances new dominance.

Challenges happen in a special realm imaginatively titled the challenge realm, you can access this realm only if you are level 150 or higher and use a portal inside one of the allegiance buildings to travel to the realm ... only during times the challenge is active can you enter the realm and once has challenge has ended everyone is returned to the normal realms.

Inside the challenge realm there is an Exile/Reaper and Society camp with a Healer and Challenge NPC, the Challenge NPC outlines what you have to do for the challenge and is also where you take the items needed to finish the challenge.

You gain the items needed to complete a challenge by killing monsters in this realm (they are tougher than normal monsters), from time to time a "Bag of Resources" is dropped and when you open the bag you gain a random resource needed for this challenge.

The number of items needed to complete a challenge depend entirely on the amount of active people in your allegiance on your server, the more people deemed active (players over level 150 who have been on within 7 days) the higher the total needed, only the highest allegiance based character on your account counts to the total so if you have multiple characters across multiple allegiances it doesnt penalize you.