This is a game mechanic available for players starting from team level 15. You can fight highwaymen three times a day, they are available from Outland interface.
After defeating the highwaymen you get loot chests and gold. You can receive up to three chests. The more stars you get, the higher the reward is. Different highwaymen have different chests as a reward.
There are three types of chests:
The green chest – contains green equipment or a green fragment.
The blue chest – contains blue equipment fragment.
The purple chest – contains purple equipment fragment.