As players progress through the early to early-mid game, they may find that they quickly accumulate the maximum quantity of gold, before they unlock the follower from Chapter 5 which allows them to increase their cap.
I’m personally working on Chapter 6 now, but I’ve found that the following strategy can allow you to spend your gold in a way that significantly improves your account progression.
Dungeons allow you to replay the final boss battle of a chapter for rewards. Aside from the gold, XP, and Chest you receive from a typical battle, you also receive a special currency: Dungeon Marks. These exist in various rarities corresponding with Chest rarities, and can be exchanged in the Shop (scroll to the bottom) with their corresponding chests. 20 Wooden Marks for a Wooden Chest, 25 Iron Marks for an Iron Chest, 25 Gold Marks for a Gold Chest, 35 Ruby Marks for a Ruby Chest, and 40 Diamond Marks for a Diamond chest.
You can also pay 1,000 Gold, which will reward you with some extra Marks at the end of battle. The most significant thing about this is that Dungeon marks can be upgraded to the next rarity. This means that after farming you will eventually be able to guarantee a Diamond chest.
The main problem here is that Dungeons are quite difficult. They scale with your hero’s level, so until you reach level 50 and can comfortably defeat the enemies within (after which higher difficulty options unlock), they are prohibitive for high level heroes to attempt.
The solution for newer players, however, is simple:
Start a new character. You can do this with the “Swap Hero” button on the Hero tab of the menu.
Progress until you complete the first dungeon. Since you can use your main character’s gear and spells here, this should be relatively easy.
Once you’ve started Chapter 2, go to the Battle tab of the menu, in the Story tab, press the back button at the top. This will take you to the world map, where you will see your current chapter, as well as Dungeons where the previous chapters were.
Click the first Chapter and you will see that the Dungeon will be at your current hero’s level. If you start the Dungeon, it should still be relatively easy since the enemies are low level, and you are using levelled spells and gear.
After about 10 Dungeon runs, by combining marks, I now have enough to purchase a Diamond chest, which I will do once I have a slot open. I don’t see any indication that level affects dungeon mark drop rates, but it does seem to affect the level of the chest you get when you spend the marks.
I hope this guide helps anyone who is struggling to find higher rarity chests.