Difficulty settings and their benefits
Certain game modes allow you to select the difficulty settings. Setting them high will not only make the opposing team more difficult to defeat but it will also apply reward bonuses.
The following game modes can have their difficulty adjusted:
Explore
Casual PVP
The Vault
Casual PVP Difficulty
You can change the difficulty in Casual PVP by opening the battle screen where the teams are shown.
There are six levels of difficulty: Normal, Hard, and Warlord I-IV. Each Warlord level requires your Hero or game to be at a certain Level to unlock the difficulty. For example, Warlord IV requires Hero Level 150.

Changing the difficulty
To change the difficulty, use the green arrows. Each difficulty level provides correspondingly higher experience, gold and soul rewards - but each higher level also further multiplies the stats of the enemies' troops.
To see the bonuses for each difficulty level, select the blue (?) icon found next to the difficulty.

The following table outlines all the bonuses for each difficulty setting.
Explore Difficulty
You can choose the Difficulty Level at the start of every Explore Run.
There are 12 levels of Difficulty in Explore. Each difficulty level affects:
Level of Enemies you will face
Chance of an Arcane dropping from the Mini-Boss
Amount of Mythstones dropped
Amount of Gold dropped
The amount of Tokens dropped by the Mythic Boss
When you play Explore for the first time, you will start with difficulty levels 1 and 2 unlocked. The next difficulty level is unlocked when you defeat the Mini-Boss at your highest available difficulty.
For example: defeating the Mini-Boss at difficulty level 2 will unlock difficulty level 3.
Unlocking a difficulty level in 1 Kingdom will unlock it for all Kingdoms.
Difficulty cannot be changed once the Explore Run begins; however, if you are having trouble, you can retreat from a normal Explore battle or lose an Explore battle to be given the option to start a new Explore Run and lower the difficulty.

The Vault
There are 4 Difficulty Levels to choose from for Vault Battles: Easy, Normal, Challenging and Hard.
Each difficulty level has enemies of different levels and provides a different amount of Rewards as follows: