Buff ability stacking

[Glythe]

Does anyone know how ability stacking works?

For example can you have 6x people at level 80 run shield team and have 16X2x6= 192 mitigation?

What about mentalism wave abilities?

[Daguin]

For buffs that stack you will generally see multiple instances (icons) in your player status window with individual timers.

[alleryn]

Mentalism wave abilities stack to 3 per wave type, last i heard.