Later today we will be applying an adjustment to the weight of Rogue class cards in Arenas to address some current balance issues. This means that overperforming Rogue cards will be seen less frequently. Additionally, we will be making changes to the card buckets for other classes to create a more consistent drafting experience. You will not need to patch your client or download any additional data to receive this update.
Please note that after this change some Rogue choices may seem sub-optimal, but we are prepared to address any outstanding issues in a future update.
For an up-to-date list of current Arena rules, please check our forum post here.