Side quests are little adventures that you can do the most of the time and does not contribute to the original storyline. A side quest can often give you something that you can use, like weapons or money. Side quests can also give you hidden lore.

A few important side quests in Breath of the Wild are-

1. Misko’s Treasure (early)

Breath of the Wild | Misko, The Great Bandit | Walkthrough Guide

• What is it about: This side quest is important and easy for the beginning of the game. 
•  Advice and helpful information: The video above is a helpful walkthrough on how to complete the quest.
• Why you should do it: Miskos treasure is good because  it gives you money as well as strong weapons which you can't normally find that early in the game.
• Why it's a good side quest: The two men who give you the quest are searching for it as well and their commentary when they tell you about it is pretty funny.

2. Priceless Maracas (early)

The Priceless Maracas - Dueling Peaks Side Quest

• What is it about: To begin the quest you must find Hestu who is looking for his maracas. If you find the maracas and the seeds to fill them he will give you inventory space.
• Why it's a good side quest:  Hestu is absolutely adorable and sings a delightful song everytime you give him seeds.
• Advice and helpful information: The video above shows you how to find Hestu, but you will need some good weapons cause you will have to fight.
• Why you should do it: This side quest is instrumental in the beginning of the game. Weapons break pretty easily in the game especially early on and this side quest helps you get more inventory spaces. 

3. Fairy Fountain (early)

Zelda: Breath of the Wild | Find the Fairy Fountain Side Quest - Dueling Peaks Tower Region

• What is it about: The great fairy fountain has been hibernating since the rise of Gannon and it is your job to get her out of her flower.
• Why it's a good side quest:  And in great fairy fashion her hysterical screams are always funny.
• Advice and helpful information: If you find the great fairy you will need rupees. 
• Why you should do it: This side quest is helpful to upgrade your gear, giving you more  defense and abilities with your clothes. There are  four fairies and if you find all four you will be able to max out almost any clothes you find.

4. Slated for Upgrades (early)

Zelda Breath of the Wild • Slated for Upgrades • Hateno Side Quest

• What is it about and why you should do it: After you meet Purah and complete her story quest she has an additional side quest to help you upgrade your slate and give your abilities more power including, faster bomb reload, the ability to use  stasis on enemies for a short time, and more.
• Why it's a good side quest:  Purah is always fun to talk to due to her child-like nature despite being such an old age.
• Advice and helpful information: It is best to do this quest early because you already have to find Purah for the original story and it doesn't take long to complete and you can get the needed materials from guardians within shrines.

5. Hylian Homeowner (mid)

Zelda: Breath of the Wild | Hylian Homeowner Side Quest - Hateno Tower Region

• What is it about: You basically buy a house before it gets torn down. 
• Why it's a good side quest:  The man you get the house from is quite eccentric as well so talking with him and his men is always fun.
• Advice and helpful information: This quest is useful for storing any weapons you like but don't want to break, like the champions weapons. 
• Why you should do it: Completing the quest also gives you a bed so you can re energize without having to spend rupees for a stay at an inn. You will need rupees to help complete the quest but not as many as the original price if you gather wood as well. 

6. Robbie’s Research (mid)

Zelda Breath of the Wild • Robbie's Research • Hateno Side Quest

• What is it about: In this quest you help Robbie restart his robot using blue flame just like Purah’s quest but longer. 
• Why it's a good side quest:  Not only that but Robbie is hilarious and has his own sound effects.
• Advice and helpful information: This quest is made easier if you buy the DLC  and obtain the majora's mask which renders you familiar to almost all enemies. You can also purchase the moblin mask from the Fang and Bone shop from kilton.
• Why you should do it: This quest is great for fighting guardians. Completing this quest will give you the opportunity to get armor and weapons that are made to work against guardians specifically.  

7. Thunder Magnet (mid)

Zelda Breath of the Wild • Thunder Magnet • Faron Side Quest

• What is it about: All you have to do is climb a stable and get an ace off the top. 
• Why it's a good side quest:  Cima’s commentary is very cute.               
• Advice and helpful information: Make sure you have a free inventory space.
•  Why you should do it: This quest is easy and gives you a piece of armor that protects against lightning, the thunder helm, the first in the set.  After that Cima will give you the helm. 

8. Tools of the Trade (mid)

Zelda Botw: Tools of the Trade Side Quest

• What is it about: A gerudo needs 10 flint to restart her jewelry business. 
• Why it's a good side quest:  Quick and easy quest. Plus, the gerudo are cool so any quest with them is awesome. 
• Advice and helpful information: Make sure you have 10 Flint.
• Why you should do it: This quest is useful for a piece of resistant armor, ice, heat, or electricity. Completing the quest also opens a shop where you can buy the other resistant armor pieces that you can't get elsewhere. All you need is ten flints which you can get from mining. 

9. Eighth Heroine and the Forgotten Sword (mid)

The Eigth Herione & The Forgotten Sword | Zelda, BOTW Side Quest Tutorial

• What is it about: Now this is technically two separate quests but they go together from the same person and in the same area. The guy you get the quest from will only give you the quest if he thinks you are female. He asks for a picture of the statue of the seventh heroine and then her sword. Which are both said to not exist. 
• Why it's a good side quest: He gives both quests back to back, underestimating the fact that you can actually find the statue and the sword. His embarrassment at the fact that you can despite being a “girl” is amusing. 
• Advice and helpful information: If you watch the whole video above you can get both pictures at the same time and don’t have to go back and forth. 
• Why you should do it: Snow and sand shoes are rare items that help you run better in snow and sand and this is the only way to get them. 

10. Fireproof Lizard Round-up (late)

Zelda: Breath of the Wild | Fireproof Lizard Roundup Side Quest - Eldin Tower Region

• What is it about: Someone in eldin is looking for fireproof lizards. If you get him 10 he will give you his armor because he won’t need it anymore. 
• Why it's a good side quest:  The full set of fireproof armor is 3300 rupees or you can do this quest and get two pieces of armor for only 10 fireproof lizards which can be found in the area you get the quest.
• Advice and helpful information: You will need a few fireproof elixirs to enter eldin but you can buy them from a woman at a stable in the entrance of eldin.
•  Why you should do it: This quest is good for getting a piece of armor as well.  To explore almost anywhere is the fire area you only need two pieces of armor so complete this quest and you can go almost anywhere in that area.

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