There are many ways to obtain Super Magical Chest and legendaries. However, I'm assuming that you do not wish to pay a lot of money on this game, so I didn't include the option of purchasing Magical/Super magical chest. However, Legendary chests are a feasible option, so that's included below.
- Attempt to obtain the chest from battle.
You are guaranteed a Super Magical Chest, Legendary chest, and Epic chest every 500 chests. That means you have a 0.40% chance of obtaining a super magical/legendary chest from winning a battle. Conditions: Arena 2 or above to get a Super Magical chest, Arena 7 or above for legendary chest - Purchase legendaries from the shop with gold
Occasionally, legendaries will appear in the shop, purchasable for 40 000 gold. This method is best if you want a specific legendary. Conditions: Arena 10 or above for legendaries to appear in the shop - Wait for the Legendary Chest Offer to appear in the shop
Occasionally, a Legendary chest will appear in the shop and can be purchased for 500 gems. This chest unlocks immediately and is limited to 1 per offer. (The offer will appear multiple times, however, usually every few weeks.) This chest guarantees 1 Legendary from any arena, but it's random, so it's best if you don't care what legendary you get. Conditions: Arena 4 or above (unverified) to receive chest offer - Try and get it from regular chests. Conditions: Arena 4 or above
A legendary is 4000 times rarer than a common card, 400 times rarer than a Rare, and 20 times rarer than an Epic. I use a formula to determine the percent chance of getting a legendary from chests.
- Silver, Giant chests - divide total number of cards by 167.
- Golden chest - divide total number of cards by 95.
- Free, Crown chest - divide total number of cards by 67.
- Clan, challenge chest - divide total number of cards by 33.
- Magical, super magical chest- divide total number of cards by 10.
Sources:
- http://clashroyale.wikia.com/wiki/Chests - card rarity, chest cycles, arena requirements for special chests
- I have friends that are in Arena 10+ and purchase legendaries with gold.
- Personal experience - purchased legendary chest on Arena 6, arena 8
- For the formula calculation: https://clashroyalearena.com/guides/card-drop-rates