6.20.2 Experience Modifiers

The following list is a non-exclusive list of things that may impact your experience gain.

Owl Tattoo         10% or 20%       Stacks with everything
Guild Bonus        10%              Stacks with everything
Statpack bonus     15% per level    Stacks with everything
Sect Essence       Up to 100%       Stacks with everything, limited to events
Elite Membership   5% to 25%        Stacks with everything
Atlas Bonus        Varies           Stacks with everything
Purple Warmask     10%              Stacks with everything
Event Bonus        Varies           Group A 
Double XP Day      100%             Group A
Wheel Bonus        100%             Group A
Soulstone Bonus    100%             Group A
Achievement Bonus  100%             Group A
Champion Bonus     100% or 25%      Group A, but 25% stacks with Group A
Increasing Promo   Varies           Stacks with everything
Favor Bonus        50%              Stacks with everything
Beans Bonus        Varies           Stacks with everything (but not with itself)

You can use CONFIG to set it so the XP modifiers that currently apply to you show up every time you gain XP.