2.5 Treasure Cave
Unlocks at lv 42. You will be able to hunt for treasure/exp mines and harvest these from the mine for up for 1/3/10 hours. You can dispatch up to 5 heroes to mine at the maximum rate and the production rate scale with your team power. All mines can hold up to 3 players. Note: If you send your hero to mercenary camp, they can not be used to mine. Also only heroes which at least level 35 can be dispatched to mine. You can only have 2 mine at any point of time unless you are vip5. Hence it is advisable to have at least 12 heroes, 2 for mercenary camp and 10 for mines.
From patch 2.1, you will no longer lose mines like before. You will be able to have a mine for the duration that you choose. Gems are dropped upon harvest for about 10-60 gems per mine (for 10 hours mine). However people will be able to plunder you and decrease your harvest when your timer is up. In addition, power recovery is decreased significantly from winning a battle in plunder (applicable to double/triple mines), so you won't have as much ease with charge up power for subsequent opponent.
Plunder requires 2 bread each attack and each bread regens per 20minutes and you can hold up to 30 bread at any time. Successful plunders will give u a small amount of loot and 2/4/6/8/10 gems (random).
This game is became very friendly with this change as most players can get more diamonds now. Also vip5 becomes very attractive for 4x mines!