Proving Grounds is another place where players may gain free resources like Gold, Experience points, Elixirs, Runes, Diamonds, etc. The Proving Grounds seems to be a place where players may "prove" their strength and their Heroes' worth as well. Proving Grounds are unlocked once your Troop Experience reaches Lvl. 15.
In the Proving Grounds, players are provided different levels and stages with varying diffiulty levels and changing rewards as well. The two main components of the Proving Grounds are the Growth Trials and Rune Trials. The Growth Trials are available once the player gains a Lvl. 15 Troop Experience while the Rune Trials are available once the players reach a Lvl. 25 Troop Experience.
For the Growth Trials, there are different types of trials or gameplay: Gold Trials and Experience Trials. In the Gold Trials, players are consistently attacked at the back row of their team. While taking part in the Exp Trials will have their enemy swarming them by the number. There are also different days and schedule for the two types of trials. The Gold Trials are available during Monday, Wednesday, Friday, and Sunday. Then the Exp trials are available every Tuesday, Thursday, Saturday, and Sunday.
Complementing the Growth trials are the Rune Trials. For the Rune Trials different stages are available:
Iron Temple wherein enemies are immune to physical damage
Empty Lands wherein enemies are immune to magic damage
Arrow Cloud Canyon wherein Tank heroes are not allowed to be deployed.