This How to you spend Dragon Quest Builders 2 Mini Medals in Dragon Quest Builders 2 page will tell you what to do with the Mini Medals you earn from solving puzzles.
The first thing you need to know is that you will not be able to start spending the Mini Medals you earn until you have completed the Furrowfield section of the main story. Once you have done so you need to return to the Isle of Awakening and head to the Mountaintop where you need to talk to the Hairy Hermit (see screenshot above). If you use the warp point you can go directly to his location. While talking to the Hairy Hermit select the prompt to 'Give Mini Medals' and he will give you rewards in increments as you become entitled to them, he will also update you on how many Mini Medals you have returned so far.
As you complete the puzzles in the chapters and earn more Mini Medals you need to keep bringing them back to the Hairy Hermit on the Isle of Awakening to unlock more bonuses. These bonuses can be a variety of things that include useful items, recipes, and cosmetics. The items you earn will be added to your inventory and the recipes will appear in your Builderpedia and at workbenches ready for creating. In order to claim the cosmetics you earn you will need to interact with a Dressing Table which will allow you to alter your character's appearance.
Check out our Mini Medal Rewards Guide to find out how many Mini medals you need to earn to become entitled to the various rewards of offer.
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