How to Look at Randomness in Hearthstone

Hi! I’m Asmodeus, multiple times Legend and infinite arena player. I’m also the author of The Complete Guide for Hearthstone Player. Today I will explain how to look at random effects in Hearthstone from a different perspective.  Using examples from outside of Hearthstone first and then translating it to real game situations which  you can […]


Hi! I’m Asmodeus, multiple times Legend and infinite arena player. I’m also the author of The Complete Guide for Hearthstone Player. Today I will explain how to look at random effects in Hearthstone from a different perspective.  Using examples from outside of Hearthstone first and then translating it to real game situations which  you can encounter, I hope to help you understand RNG effects and how to play around them.

Since random elements of the game are often the source of frustration among players, a better understanding of them will not only help you make better plays but it will also help you stay cool and collected.

Learn from poker players

Adrian “Lifecoach” Koy, who used to be a poker pro, is a great example of someone who can get an edge in Hearthstone just by knowing how to approach RNG cards and effects. The elements of being a successful Hearthstone player overlap with the elements of being a successful poker player in many places.

  • Understanding of probability and statistics on a basic level
  • Correct attitude
  • Long term thinking

He and many others were able to transition those skills to Hearthstone. Since Hearthstone is a game focused entirely on your decision making, those skills are crucial to success.

Players coming to Hearthstone from other games, where chance is a big factor are going to be more used to dealing with frustration and tilting. I recommend that you look into the basics of poker and learn some of the poker strategy, as it will help you gain a deeper understanding of card games and games with random elements, including Hearthstone. You can start by checking out the TwoPlusTwo forums

The coin example

The example I like to use, when explaining how to look at randomness is a simple coin bet. Imagine that we make a wager with such conditions:

  1. One of us throws a coin (we assume it’s a fair toss with 50/50 chances)
  2. If it comes up heads – I will give you $2
  3. If it comes up tails – you will give me $1

Would you take that bet? Of course you would. If we flipped the coin a hundred times, I would have to pay you about $100 and you would pay only $50, giving you a profit of approximately $50.

But what about just 1 coin flip? If we made that bet, but agreed to do it just once and it came up as tails, making you the loser would it still be a good bet for you?

The answer is – yes. Before we see the outcome, you have no way to know the result, but what you do know is the Expected Value. Just like we can tell how much money you’ll gain in a hundred coin filps, we can also calculate how much money you’ll make in 1 coin flip. You simply add the possible outcomes and divide it by the number of possible outcomes.

[2 + (-1) ]/2=0.5

Which means that with each coin flip you can expect to earn $0.5. You can see that it adds up when we multiply it by 100, because we get the same $50 as in the first example.

Expected Value in Hearthstone

Let’s see this now on a Hearthstone example. We’ll take a look at the boom-bot. Often people just throw it into something and hope for the best, but how much damage should you expect them to do? Let’s use the formula from our coin example. We add the possible outcomes: 1+2+3+4 and divide it by the number of possible outcomes: 4.


Which means that you should expect a single boom-bot to deal 2.5 damage and 2 of them will deal on average 5 points of damage. Of course a single hit from the boom-bot deathrattle can not deal 2.5 points of damage, but that’s the number you should be expecting. If you predict a target to be hit by one of the bombs, you should play as if that bomb would kill a 2 health target, but not a 3 health target. If you expect a target to be hit by two bombs (for example you wipe the board with hellfire killing all minions in the process and sending the bombs to your opponents face), you should make your decisions as if the bombs dealt 5 points of damage, because that will be the average outcome.


Your attitude toward RNG is very important if you want to make the best decisions. What’s most important is that you make your choices based on what is most probable and not based on the actual outcome.

Let’s say that you played arcane-missiles against a single worgen-infiltrator and none of the missiles hit that worgen, leaving him alive and making you waste a spell. You should never let this outcome influence how you approach similar situations in the future. Once you know that the probability of killing a single 1 health minion with arcane-missiles is 87.5% you just realize that this is the remaining 12.5% and you simply got unlucky. You should stick with making that play because it has a great chance of success.

People tend to remember when they get unlucky rather than when everything goes just fine and I’m sure it will seem like you have bad luck and bad RNG much more often than you would expect, but that’s simply how people see things. Become aware of the bias that makes us notice and remember negative events much more than the average or positive ones, so that you can separate your decision making from it. Always try to figure out your chances and pick the option with the highest rate of success.

If you’re not certain about your calculations or want to confirm them, make sure you’re collecting hard data. Your memory can’t be trusted on this. Some time ago I’ve been facing a lot of warriors that seemed to always have fiery-war-axe by turn two, so I’ve started to mark on a white board next to me, each instance of enemy warrior having or not having fiery-war-axe at the start of the game. Sure enough after 20-30 games, what felt like “almost every time” was actually just above 50%, exactly as expected if you calculate the probability.

Everyone gets their share of bad beats, unlucky draws and terrible RNG, the better you learn how to cope with it, the better your decisions will be. Those 5% and less chance events have to occur sometime, and they will happen to you over the course of your Hearthstone adventure a lot of times. Whenever that happens, try to just accept that this is one of those moments and realize that you’ve done nothing wrong if it came just to the RNG and you did everything you could to put yourself in a favorable position.

Considering stakes in Hearthstone

Despite many similarities, Hearthstone is still it’s own game and differs in many ways from poker. One of more important differences is the evaluation of stakes. While the outcome of each poker hand can vary wildly in terms of how much money you win or lose, the outcome of a Hearthstone match is always binary – win or lose (with the rare exception of a draw).

When you take a risk, you should also try to approximate how important it will be in terms of you winning or losing the game. For example:

If the enemy has a damaged dr-boom with 3 hp left, and you have a darkbomb and imp-losion in your hand, but only enough mana to cast one of them, which one should you use? We already know that we should expect implosion to deal 3 damage, but we also know that 33.3% of the outcomes will result in dealing only 2 damage. If you’re low on hp and dr-boom surviving lowers your chances of victory drastically, you should not take the risk and simply use darkbomb. If your hero is healthy but this time your enemy is on low health and you realize that having few imps on the board will greatly increase your chances to win, then you should take the imp-losion route.

With experience you’ll gain a better understanding of the importance that each choice has for the outcome of the game and that will let you know when to take a bigger risk. Sometimes you’ll be in a very bad spot where the safe option will just not be enough and you will need to take a risk in order to make a comeback.

Closing words

I hope this helps shed some new light on randomness in Hearthstone and how you can look at it to facilitate your decision making process. Remember that everyone gets both, lucky and unlucky moments in Hearthstone and keep your chin up when the latter happens to you. It’s just a part of the game.

Share your opinions and post your questions in the comments, I’m always happy to answer them.

You can also find more of me through my social media:




I’m available for Hearthstone coaching – you’ll find all the info you need here: Coaching with Asmodeus