This feature no longer exists.
Marauders are tough PvE enemy Heroes (or groups of Heroes) that can be fought from the Friends list. Searching for Marauders unlocks at Lv 36.
Every eight hours, players can scout for Marauders. If a player does not encounter a Marauder, typically, a large amount of Gold or Spirit is found, and added to the player's resources. Once a Marauder is found, it is visible to all Friends of that player.
To battle against Marauders, players spend a Stamina point to battle once against a Marauder. Stamina points regenerate at a rate of 1 per 2 hours, and are capped at 10 points. Each battle grants points counting towards a player's ranking in 'Help Fight', which resets every week. Higher level Marauders grant more points per damage.
Marauders have an extremely large HP pool, but a normal attack. It is fully possible to last until the 15-turn limit, especially with the help of a healer. Damage dealt to the Marauders is kept from battle to battle, and the percentage of HP left is shown before battle.
Defeating a Marauder gives the player who encountered it, and the player who defeated it, an amount of Gems, depending on the level of the Marauder.
During the rework of this, this has been replaced with the Lost Underground.