Welcome to my guide, I hope you'll like the short read. :)
I'll explain a few key mechanics in this game and then explain how you can achieve the best result for spending your gems.

There are currently 4 chests in the game.

• 100 gem chest
  
• 250 gem chest
  
• 500 gem chest
  
• 1000 gem chest

As you expect, you will get a better reward if you open the most expensive chest.

Key mechanic #1:
You will never get the same ring/amulet twice

What does that mean? It means that when you have all legendary, rare and uncommon items and you open a 1000 gem chest, you will receive a bag of 1000 gems. In other words, the game tells you there isn't an item anymore that you can buy with this chest.


Key mechanic #2:
The list of amulets/rings is pre-defined.

This means that after a certain point, you can no longer get any item from a chest.


Key mechanic #3:
Each chest drops a different set of rings/amulet with some overlap between rarity
1000 gem chest often drop uncommon, but they can also drop rare and legendary.
100 gem chest often drop common, but they can drop uncommon after all the commons are gone.
And then they drop rare when all uncommons are gone.

If there are no more rare drops left, the 1000 chest will surely have to drop something better!

If you can combine this knowledge, the recommended approach is at follows:

Buy only at 100 gem chests until you can no longer buy from it.
Then buy only from 250 gem chest until it drops no more.
Next up is 500 gem chest.
Finally the 1000 gem chest.

This will be the cheapeast and thus fastest way to get all items in the game.

Here's a list of all the items you can obtain with gem chests

• 24 common
  
• 71 uncommon
  
• 41 rare
  
• 7 epic
  
• 19 legendary

1000 gems chest can drop uncommon to legendary
100 gems chest can drop common to rare.

If you purchase only 1000 gem chest, it'll cost:
71+41+7+19=138k
with 24 common items left for 2.4k gems worth
Total: 140.400 gems.

If you purchase only 100 gem chest, it'll cost:
24+71 + 41 = 136 * 100 = 13.600
7+19 = 26 items left
If you use 1000 gems for these it'll be 26.000
Total: 39.600 gems.

Doing it the perfect way**:
24+71 * 41 * 100 = 13.600
7 * 250 = 1.750
19 * 500 = 9.500
Total: 24.850 gems. ( 22.365 gems with 10% discount )

As you can see, the difference is huge, you can save more than 100k gems!

** The perfect way also means you get the best weapons the last, so if you want to gamble to get the best weapons earlier, you're free to choose your own path.

• You can even save some money with the 10% cheaper purchase ring/amulet. (Does not stack)
  
• Use the abovementioned amulet/ring and you can cause an infinite amount of gems. Simply make sure that 100 gem chest don't drop any loot anymore and return you a bag of 100 gems. This way you buy for 90 gems and receive 100 gems in return.
  
• You can rush certain bosses like Kephri to get a good amount of gems fast.
  
• Battle challenges also provide good amount of gems, look for orange pillars.

Thank you for reading, leave a comment and/or a thumb up if you like this guide.