This post contains my thoughts on the game design in Hearthstone. Since this is about an ever changing online game it is important to note that I’m writing this as the League of Explorers adventure is the newest content available and wild and standard have just been announced as a change to the format. It is quite likely that the game might have changed significantly in the future – for better or worse.
So what is Hearthstone? It is an Online Collectible Card Game (or CCG) made by Blizzard Entertainment. It is similar to traditional Trading Card Games like Magic: The Gathering or Yu-gi-oh, but in Video Game Format. For context I recommend to either play it before reading (it’s free to play) or at least watch a video of someone playing it. But in summary: 2 players; play cards; attack opponent; win. Good stuff. And simple enough.
Which brings me to my first point. Hearthstone is well known for being a really really simple game. There are certainly several reasons for that. First the win condition isn’t particularly complicated – you just reduce the health of your opponents hero to zero. The resource management is almost completely removed compared to games like Magic, since mana automatically increments every turn up to a total of 10. Similarly, the game doesn’t split each turn into different phases like other CCG’s tend to do. There are no interruptions and you can play your cards and do your attacks in whatever order you want, making it rather straightforward.
But I think the biggest reason it is so simple and easy to pick up is due to its nature of being a video game. Hearthstone does a great job of using visual aids to guide the player. Cards have a green border when they can be played, even changing the color of the border when a specific condition is fulfilled. There is also no need for a lot of card text, since the players don’t have to resolve the effects themselves. Just play a card and see what happens. The card text only needs to give the player an idea of what’s going to happen. The game is also paced quite fast with relatively low health totals so games are over quickly.
That being said there is a trade off to be made here. Hearthstone games just don’t feel as large or impactful as playing a card game in real life. Think of a card that deals 3 random damage to any character (Mad Bomber) for example. To play a card like this in real life you would need to assign a number to each occupied slot on the board, and throw a dice with these numbers three times to get the effect resolved. And while doing this over and over would be quite a hassle, it would also make playing mad bomber a more meaningful experience in the game. The developers do try to recreate this effect by making the animations of the game very physical and they really do a pretty good job there. In the end the quick card resolution accelerates the games even further, resulting in hearthstone being a game designed to be played in short sessions in between.
So since Hearthstone is basically baby’s first CCG it must be lacking depth in its gameplay right? Well yes and no. Lacking some features like different phases certainly limit depth to a degree. It is worth noting however that depth does not necessarily equal complexity. A game can be quite easy to play but still have a huge depth. Just look at go for an example. It is however true that complexity is one way to create depth. If a game is hard to pick up to begin with, it will always have a high skill ceiling. I’m looking at you Europa Universalis 4.
Hearthstone introduces depth with several mechanics. First there are the classes. Every class has different class cards as well as its own underlying concept. Shamans and Druids actually do have a form of resource management with their overload and ramp mechanics. Rogues on the other hand have to be aware of how many cards they have in hand since they depend on playing multiple cards on the same turn. Splitting these mechanics into the different classes allows the game to have decent depth without sacrificing its simplicity for it. Since the pool of cards has to be split among the 9 classes though, this can sometimes make the options feel limited.
Another reason why Hearthstone is a rather deep game isn’t really due to good design though. The game just flat out doesn’t tell you its full rule set. While I praised how the game doesn’t use much card text, because really seeing LORD JARAXXUS – EREDAR LORD OF THE BURING LEGION played once is usually enough to understand the card, some things just aren’t that easy. I’m speaking of the so called “hidden rules” of Hearthstone. To give a few examples:
- Buffs can be silenced, Transformation effects can not. Cards do not specify which effect they use.
- When two or more minions with a deathrattle die, the effects will be resolved in the order they entered the board.
- A Hero can only have a maximum of 5 secrets in play at the same time.
- A minion at zero health can still trigger its effect.
The problem is this information can not be found in the game. In general the game follows a depth-first approach to resolving plays. These things might seem a bit obscure, but as someone who played the game quite a bit I can say they really are not. Not to mention that some of these rules have exceptions; simply because the cards have been coded differently. I believe a rulebook accessible from within the game for these kind of things would help a lot. As it stands, Hearthstone gains depth by forcing some trial and error out of its playerbase, which really isn’t ideal.
Skill and Luck
I do consider Hearthstone to be a rather skillful game. Not everyone would agree though. A lot of this comes due to the very type of game it is. If you’d ask someone if they think chess is a game of skill the vast majority of people would probably say yes. If you’d ask the same for poker however the answers get much more varied. Poker players with a lot of games would say yes, while there will be a decent amount of people saying its all luck.
From a game theory perspective Hearthstone is a zero-sum game with imperfect information. Zero-sum means for every player who wins, another one has to loose. Imperfect information means a player doesn’t know everything about the current gamestate. In Hearthstone the hand of the player and the opponent, the board and the remaining cards in both decks make up the gamestate. Only the players hand, the board and the amount of cards the other player has are the visible gamestate however. The thing about these kind of games is that their skill isn’t perceived so easily. In a game with perfect information like chess, the better player will win every single game unless he makes a mistake. With imperfect information however, the better player will just have won more after a certain amount of games, since making an educated guess about the hidden information just isn’t as reliable as knowing everything. This is obviously simplifying game theory a bit but that’s the gist of it.
What this means is that tournaments with a best of three format are kind of silly in my opinion. It’s like having poker players play 5 hands before deciding who won.
Hearthstone however, further complicates this by introducing a large number of cards with random effects on top of the inherit randomness of the imperfect information. I’d like to talk about what I think these random cards add to the game, before I actually judge their impact on the level of skill the game allows for.
The first thing that comes to mind for me is, funnily enough, the increased skill ceiling. A Random effect creates a branching path of possible outcomes for which the player has to account for. Similarly the game can be manipulated to make the random effect work in your favor every time. Cards like Crackle and Bomb Lobber are good examples for cards like this. Bomb Lobber in particular is 100% reliable if the opponent only has one minion on board. Learning how to use cards like this effectively is part of the challenge and the game would be worse without them.
Then there is the increased design space if a card game allows for random effects. Simply stated: a random card can have a higher power level since it has some potentially bad outcomes. Ysera is a good example of this. Ysera gives the player one of a specific set of dream cards at the end of their turn. All these cards are powerful, but some are more useful then others. If the player was allowed to choose a specific card, Ysera simply couldn’t exist even if the cards were to be nerfed.
Next random cards exist to keep the simplicity of the game intact. Imagine playing Knife Juggler, a card that deals one damage randomly whenever the player summons a minion, but with his ability being targeted. Play a minion, choose where to deal one damage, play another, choose where to deal one damage. This would make the interface cluttered. This is probably why there are no targetable persistent abilities in the game right now. And while I certainly hope targeted minionabilities get implemented one day I can see why this wouldn’t work with some interesting cards.
The last thing here are “player stories”. Blizzard keeps bringing this up when talking about randomness so I might as well. This means that randomness can make for memorable games. True enough, a lot of wacky things can happen in Hearthstone. While I had these games and I can see why the designers would want the players to experience this, personally I think it potentially sacrifices the consistent enjoyment of the game for the occasional spike of enjoyment.
So randomness isn’t really a bad thing. It makes it harder to perceive skill, but can also increase the real skill required on top of many other positive effects. That being said, there a couple of cards which take randomness too far and become problematic. And yes I’m aware we are (sort of) rid of most of them very soon. That doesn’t make it less useful to talk about them for future reference.
This card is probably the embodiment of the “player stories” philosophy. It can be great fun but it is completely independent from any player skill. Creating any minion in the game is just too much of a variance to be able to plan ahead. It’s a card that you play and hope it benefits you.
Shredders …and a raptor
These cards have the same problem but to a lesser degree. Since battlecry effects get taken out of the equation for their summons they are a lot more predictable. The problem they suffer though is that they, as well as unstable portal, will constantly get stealth buffed/nerfed when new cards get introduced. Cards that interact strongly with a huge chunk of the card pool are unpredictable three expansions down the line.
This is just dumb. I’m sorry but it is. Stacking two random effects on top of each other is just bad design, and having to see them resolved twice each time Dr. Boom gets played is just asking for trouble. The variance on this is just through the roof.
So the problem really isn’t randomness, it’s variance. Random effects are perfectly fine as long as they have a level of predictability. The good news is that blizzard seems to have found a nice middle ground to this. The at the time of writing newest adventure of the game (The League of Explorers) introduced the discover mechanic, which lets you pick one out of 3 random cards of a specific type. These cards do have huge variance but they even out in the end. 3 bad cards will always have one more useful then the other, while you can still only pick 1 out of 3 great cards. Furthermore these cards go to your hand without any cost reduction so they remove the tempo of unstable portal and shredder. This allows players to play with unusual cards, while still including players choice. It is a great mechanic and I hope future high variance cards will learn a lesson from it.
In the next part I will talk about the various game modes as well as the business model and whatever else I can think of.
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