Booster Items

Booster items temporarily ramp up your gains: extra XP, Ancient Energy, ore, shards, or Hunter XP, for a limited window. Personal boosters affect only you; global boosters stack a bonus for the whole server while they're active.

For how booster bonuses stack and tick down, see Boosters. Many of these drop in crates, boxes and keys, especially the Simple, Elite, Ultimate, Legendary, Godly and Global Booster Boxes.