Hearthstone is a collectible card game by world-class developer Blizzard Entertainment. It has taken an entire generation of casual and professional gamers alike by storm. So many people play it, chances are you’ve already sunk some money into it. So, if you’re going to pay a little anyway, you may as well get a discount.

Amazon is currently selling Amazon Coins at a 4 to 15% discount based on how many you buy. Blizzard allows payment via Amazon Coins for their in-game purchases, so you can receive anywhere from a 4 to 15% discount on Hearthstone packs or other in-game items by paying with Amazon Coins.

Additionally, you can “earn” free Coins from Amazon by purchasing in-game items in any of Amazon’s promoted games. More on that later.

Step 1: Open Appstore (Kindles Only)

If you’re using a Kindle Fire HD or other Amazon model, just head to the Appstore, open the side menu, and select Amazon Coins.

Step 2: Install Amazon Underground (Other Android Devices)

For all other Android devices, install the Amazon Underground app using our installation guide. Once installed, launch the app, sign in, open the side menu, tap on the arrow next to Underground Apps, then select Amazon Coins.

If you don’t see this option, you’ll need to install the older Amazon Appstore for Android app instead. Just download the newest APK for it, then sideload it like any other APK file. Once done, open it up, sign in, open the side menu, then select Amazon Coins.

Step 3: Buy Coins

If you don’t have any Amazon Coins at the moment and need some fast, select “Buy Coins” and select the number of Amazon Coins you wish to purchase, then complete the checkout procedure using your default Amazon payment method.

No matter which app you’re using (Appstore on Kindle, Appstore on Android, or Amazon Underground on Android), you’ll see the same discounts on Coins. They occasionally have better deals, so keep an eye out for when that happens.

Step 4: ‘Earn’ Coins

Amazon will occasionally offer free Coins if you complete certain offers, but as of right now, the only way to earn more Amazon Coins is to purchase in-game items in select games using your saved Amazon checkout payment method or your current Coins balance. You can currently get up to 30% back in Coins, depending on the in-game item.

If you’re on a Kindle, just select “Earn Coins” on the Amazon Coins page in the Appstore to see which games have in-game items with free Coins back. If you’re on another Amazon device, you can view the list here, as there is no “Earn Coins” option available directly in the Amazon Appstore or Amazon Underground apps.

Step 5: Install Hearthstone & Use Coins

Next, download the Hearthstone: Heroes of Warcraft game from Amazon Underground. It’s very important that you get it from this source—if you’ve installed the app from the Google Play Store, you’ll first need to uninstall that before installing it from Amazon Underground. Your game data should be synced with your Hearthstone account, so you don’t have to worry there.

Open the new Hearthstone app you installed from Amazon Underground and sign in as usual, then go to the shop and select the number of packs you wish to buy.

On the checkout screen, tap the option to pay with Amazon Coins. Then, tap on Purchase. Aside from the discount you got when you purchase or earned Coins to use for this packs purchase, the packs themselves should be cheaper on Amazon than if you were buying them from the Google Play Store, so it’s even more money saved.

Enjoy your new packs. Go forth, and may the RNG gods be forever in your favor. And may you pull many legendaries.

Let us know in the comment section below what you think of using Amazon Coins, or drop us a line on Android Hacks’ Facebook or Twitter, or Gadget Hacks’ Facebook, Google+, or Twitter.