The Other Side – Card Rarity Systems VS Game Balance

Hi Everyone, for this week’s instalment of “The Other Side” we look into card rarity systems.

I hope your first week back to normal life after the winter break has been a super easy transition. This week’s post is the second article I wrote for my original blog. I wanted to post this one early as I think it’s one that this audience would get a lot out of.

For our first dive into Business vs Games Design I want to focus on something that is considered an industry standard and break it down. Today’s topic will be rarity in games and how it impacts the overall design. As mentioned before I can’t talk directly about the game I worked on, so I will be taking a look across other successful games to help you walk through my train of thought. When it comes to Trading Card Games (TCGs) or Collectible Card Games (CCGs), your local game stores every day are buzzing with people cracking open packs of cards (Booster Packs). Players are looking to build their collections and trade off the cards they don’t need for the ones they do. In most cases, the players are chasing rare cards, because they are harder to come by, as the name implies. As a quick 101 of card games, almost all of them use a rarity model to determine how often certain cards appear in packs. A common model is as follows:

Common cards – Make up most of the pack

Uncommon cards – Usually a few in a pack

Rare Cards – Normally only 1 in a pack

Epic/Ultra Rare – 1 in every few packs (consider a ratio of 1:6 as pretty normal)

Legendary/Mythic/Secret Rare – Maybe 1 or 2 in an entire box of boosters (consider 1:30 or 1:12 depending on the number of boosters in a box).

With this in mind, today’s main question: Is a game balanced if it is using a rarity model to acquire assets that give an advantage in game? My answer to this question is no – the game is not balanced, but it makes for an excellent business model. 

The game of choice I want to look at is Magic the Gathering (MTG). MTG is the grandfather of the entire TCG/CCG industry. The concept is pretty simple: each pack contains cards, with some of them harder to get than others. The issue is that with those cards that are harder to get, there needs to be a reason to make you want to chase them.  If a rare card and a common card were equal in power, there would be no reason for players to purchase more booster packs looking for the rare cards. So immediately, we are approaching the design with the perspective that some cards will be better than others. This can be fine – if everything was equal, we would be playing chess or poker, which can be less exciting and ultimately sell less units. Here are some examples of cards from MTG to illustrate the power level difference between cards of different rarity, even within the same product:



For reference, the card rarity is denoted by the color of the set stamp: black is common, silver is uncommon, gold is rare and orange is mythic rare (the hardest cards to find in packs).

In Magic the Gathering, cards have costs referred to as mana costs. This tells you how much of the in-game resources you need to pay to play certain cards. All of the cards for this example cost 4 mana total. As you can see, our common card the Bristling Boar is the weakest card of the group, with stats of 4/3 and only 1 ability. The step up from this is the uncommon card Gnarlback Rhino, which also costs 4 mana but is a 4/4 and has 2 abilities. The Nightpack Ambusher is our rare card: a 4/4 with 3 abilities. Lastly Vivien, Arkbow Ranger is the mythic rare card. Unlike the others, Vivien is not a creature, so it works differently. The short explanation is that you can use 1 of the 3 abilities on this card every turn, as long as you pay the cost, which involves placing or removing counters from this card. For players that do not play MTG, the strength of the abilities scale up depending on the rarity of the card; for example, the Nightpack Ambusher’s 3 abilities are all significantly stronger than the Bristling Boar’s.

In-game, all of these cards effectively cost the same number of resources to play, although it’s worth noting that the more tree symbols you see in the top-right of the card, the more specific the resources you need to play the card (which impacts the card’s power – the more specific the cost, the bigger the payoff needs to be). Additionally, the in-game return on investment for playing a card rapidly scales with the rarity of the card. If a player is going to commit some resources to playing a card, there is no real reason to ever include the Bristling Boar in your deck when you could be playing Nightpack Ambusher. Of course, the Nightpack Ambusher is a rare card, which means it is much harder to find in packs than the Bristling Boar. In fact, when you open a booster pack, there will be 10 common cards, 3 uncommon cards, and 1 rare or mythic rare card, so you are already 10x more likely to find a Bristling Boar in your pack than a Nightpack Ambusher. And this is before you even consider the actual odds of pulling any 1 particular rare or mythic rare card from a pack.

The actual set breakdown of the Core 2020 expansion containing all of these cards is as follows: 112 common, 80 uncommon, 53 rare, and 15 mythic rare. So this means from a customer’s perspective, when you open a booster pack you have a 1:53 chance of finding a Nightpack Ambusher (caveat: your odds are actually a little worse, since rare cards get replaced by mythic rare cards in packs when they appear).

If a card is going to be harder to get, there has to be a reason for players to want to get it. This means the power level has to be higher than cards of a lower rarity.This inherently unbalances the game, as the lower-rarity cards will be at a disadvantage when played against rarer, stronger cards. This is not to say that a rare card always beats common cards; there are a number of factors to consider, such as card type, synergies with other cards in your deck, etc. But generally speaking in terms of value for the player to play the card, the higher the rarity, the better the return on investment for playing that card. On the business side, this is great, as it translates booster packs into consumables that immediately lose all value when they are opened. This means players have to either keep buying new packs if they want to get the cards they need, or go to the secondary market (single card sellers) to find someone that already opened a pack(s) and has the card(s) they need. By having higher-rarity cards, you also create the demand for multiple re-purchases from customers that have already brought packs. This means in the design process, you are already accepting that for the business model to work, you will need to create cards that are significantly better than others in order to create a chase element to encourage repeat purchases.

If a card is a higher rarity and it’s not strong, players will get very vocal and very angry that they feel cheated out of a strong card.

Card rarity is an influence of the business side to generate higher volumes of sales. Truth be told, this is one of the most successful business models ever conceived in gaming. Card games such as Pokemon, Magic the Gathering and Yu-Gi-Oh! make significantly more money than most released video games every year; in fact, I would argue that very few video games have ever exceeded the success of one of these card games (World of Warcraft and Grand Theft Auto 5 are the level of game that you have to produce to out-perform any of these 3 games). You can see how successful this business model is when video games started including loot boxes. A loot box is a digital booster pack designed to give the customer the same rush of excitement that they may open a rare and powerful item while encouraging repeat purchases. Players in a game’s life span will spend significantly more money on smaller, cheaper boosters than they will buying a new game off the shelf.

A digital booster pack

This business model only works if all cards or items within the booster packs are not equal. As such, the game balance is compromised by the very nature of this business model. An argument could be made that rarer cards are balanced against each other as they have the same number of abilities or stats that make them line up well against one another. I would argue that this is not representative of game balance, since you still have situations where cards like Bristling Boar are never going to stand up to a rare card of the same resource cost.

The main reason for common cards in packs is to generate the casino jackpot effect in a customer’s brain when they find a really rare card in a booster, which has been massively pushed in digital games such as Blizzard’s Hearthstone. When you hit a legendary card (the highest rarity card in Hearthstone), you get a huge visual and audio reward to hype the customer’s excitement. The game then tells users on your friend lists the card you opened to encourage them to message the customer and congratulate them even further, reinforcing the good feelings you get from opening a booster pack while even encouraging your friends to try their luck on some packs. In the long run, this creates a mental trigger in the customer’s brain that begins ramping up excitement before they even open a booster; the customer actually feels good ripping open the pack and inspecting the contents. This feeling is addictive and leads to customers coming back over and over again to purchase new cards. The dopamine hits that customers get from opening packs is a huge rush, and unlike more harmful habits like smoking or drinking alcohol, you get social validation and attention from other players when chasing the rare cards.

In the long term the process ends up looking like this:

Customer buys pack – > gets rare cards they needed – > gets excited and social validation from other players – > customer buys pack -> customer doesn’t get rare card they needed – > feels compelled to try again.

If all the cards were balanced against each other and there was no rarity model, you would lose out on this almost endless feedback loop because players would have no reason to get excited over any particular card. This is an excellent example of business vs game design: if true balance was the goal, you couldn’t have cards that were significantly stronger than others. By adding a rarity model to your game, you increase its life expectancy dramatically while also opening yourself up to huge profits and high volumes of sales.
A game doesn’t have to be perfectly balanced to be fun – in fact, the randomness of card games in general what is makes them fun and successful. At a later date I will write a post on random vs consistent games and the impacts on sales as a result.I want the takeaway from this article to be not that I don’t think games with rarity models are bad, but that from a purist’s game design perspective, they are inherently unbalanced and geared towards increasing sales.

A question for you guys: When Blizzard Entertainment’s Diablo 3 was released, there was a real money auction house where players could sell items to other players. This was largely used to sell rare items, which necessitated that rarer items needed to be significantly stronger than more-common items to encourage sales with that service. By my definition of game balance and the article above outlining my personal thoughts, I would argue this was an unbalanced game. Once the real money auction house was removed from the game, but the item rarity was left in, did the game become balanced? Once the incentive to engage in micro-transaction were removed, did this balance the game and make loot just fun to hunt? I could honestly argue this both ways, but I would be interested to hear your thoughts, feel free to throw them in the comments section below or shoot me a tweet


– Matt


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