What makes a card game exciting? At their heart, card games introduce a degree of unpredictability and resource limitations through random card draws. These factors in turn enable players to respond with creative and exciting strategies with their limited knowledge and resources.
With their potential for captivating gameplay, the card-based formula is a mainstay in popular culture from Poker to Pokémon, and more recently to the medium of video games. Yet within this overarching genre are two very different – and sometimes incompatible – playstyles: card collection versus hand optimization. In prioritizing one mechanic and playstyle over the other, game designers unfortunately lose some of the exploration available to players, whether that be discovering new cards or experimenting with the power of drawing a hand. The genius behind Slay the Spire, due in large part to its rogue-like mechanics, is its ability to synthesize both of these playstyles.
Before continuing, however, it is important to define terms and examine the development of card games as a genre of play.
Whenever someone draws a card, two important questions arise. First, what is the card in question? And second, what other cards can be drawn next?
The first question lends itself well to a focus on card collection. Players focused on having the best card in hand at all times should invariably want to collect the best cards available. “Card collection games” like Pokémon and Magic the Gathering fit into this category by rewarding and encouraging players to add new cards to their existing decks. Yet if left unchecked, this playstyle has the potential to overly encourage consumerism. The 2021 shortage of Pokémon cards and the success of Genshin Impact’s Gacha system (paying and gambling to unlock characters) highlights the potential for cultures to form around the act of collecting cards, sometimes ahead of exploring other game mechanics.
The second question when drawing a card matches a hand optimization playstyle. At the extreme, traditional card games like Poker or Hearts rely entirely on the randomness of card draw for interesting gameplay. All players start with the same collection of cards and must instead focus on predicting what will be played next (i.e. card counting) to win. Yet a limitation of this model is the inability for players to experiment with different card combinations outside of a small sample size. A game of Poker may become mundane for players once learning the few card combinations available. Most of the fun of these games arises from other factors outside of card draw, such as gambling or bluffing. In short, games that focus entirely on either card collection or hand optimization restrict the opportunities for players to experiment with the act of drawing cards.
One game that makes a good attempt at combining these two playstyles is Stormbound, a mobile game for the IOS. By completing challenges or purchasing loot boxes, players gain cards that can be leveled up and added to their deck, akin to the focus of a card collection game. Yet compared to other card collection games like Pokémon and Magic the Gathering, the game promotes more mindfulness of deck construction. Players are limiting to 10 cards at a time and must cycle through this small deck throughout a match. As a result, players cannot rely on a single overpowered card and must instead synergize their limited, but recurring resources. Nonetheless, the role of card upgrading and loot boxes should not be understated. There is a ceiling to how far a player can advance without having spent significant in-game currency to upgrade cards to their max level. Due to this, the game can turn away new players.
What impressed me most about Slay the Spire, in comparison, was its ability to present players with opportunities to engage with both playstyles. The game does this in three ways: (1) repetition through death, (2) multiple options for card removal and additions, and (3) card cycling.
As a rogue-like game, each time a player dies in Slay the Spire, their deck is reset to its starting position. Although this might initially appear frustrating to both card collectors and hand optimizers, I would argue that this simple repetitive act enhances gameplay for both. By losing their collection, players are told that their diversity of cards is an important gameplay mechanic and that there are high stakes for preserving this strength. Players are encouraged to quickly restock their collection and are given ample opportunities to do so; after each level, players are given three cards to choose from to add to their deck.
The frequent death of the character also forces players to experiment with new strategies on each run to advance further. This repetition should familiarize players with counters to potential enemies and encourage premeditated deck construction to ensure that these cards are available to draw at a moment’s notice. Finally, based on how far a player advanced on their most recent run, their character can be upgraded to unlock new cards to discover along their journey. In this way, restarting on each run allows players to engage with both playstyles.
Game mechanics also force players to regularly confront the tension between card collection and deck simplicity. As with Stormbound, having cards cycle from the discard pile to your draw pile makes card drawing a key mechanic of gameplay. It is important to note, however, that Slay the Spire lacks a maximum number of cards that can be held at once, unlike Stormbound. This successfully forces players to consider each playstyle when building a deck. A large deck with a diverse array of cards may be able to deal with any threat that arises (card collection), while a smaller deck more carefully constructed should ensure that better cards cycle back to the draw pile more frequently (hand optimization).
These conflicting foci continue to arise throughout gameplay because the game offers opportunities to shift one’s strategy in the middle of a run. After each level won, players are given the option to add cards or reject them. Similarly, the merchant character can be paid both to gain cards or remove cards from your deck. Therefore, players must confront the decision to expand or reduce the size of their deck after nearly every level, making card draw a core part of game strategy.
Future card-based video games can learn from the example of Slay the Spire by building in mechanics that enable players to experience a combination of card collection and hand optimization. Without this, a truly immersive card game experience will be harder to achieve.
I found this blog post fascinating, even as someone not super well acquainted with card games. My introduction to them was Hearthstone, and the most recent one I played was this one, Slay the Spire – and these are the only two I have ever played. Despite this, I really like both games, and have given them a lot of thought, especially recently. I never really approached thinking about the design of either game in terms of “decks vs. hands”, so your approach in this blog post opened up a lot of new insights. I wonder if a third concept, a card library, can be introduced to your analysis. In hearthstone, your library would be all of your available cards, and in slay the spire, it would be all the cards you get throughout a run, including the ones you discard. Certain card games (like the one you mentioned, Stormbound), and poker, wouldn’t have a “library” under this definition, but I would be interested to see what considerations this could bring with the ideas of decks and hands. What, for example, makes a card from a library worthy of including in a deck?
I think this analysis of how the rogue-like structure of Slay the Spire applies to two separate styles of card games is very interesting, mainly because as mentioned in your blog post, games that are both considered “card games” like poker and Pokemon play very differently, despite sharing a core mechanic. In the case of Slay the Spire, I think the title of “card game” is also slightly misleading, since there are non-card pieces that the player also can utilize, namely that of relics and potions, and I think this is a large part of what makes Slay the Spire much more replayable. A deck in Slay the Spire that would otherwise lose to a particular boss could sometimes go on to win a run with the addition of a single relic or potion used in the right way.
Every character has about 70 different cards that can be presented to the player, and even though there are a good amount of synergies between the cards, there are also a good amount of cards that all have similar effects. For example, the Ironclad’s card pool leans towards cards that can output big damage, and the Silent has a heavier focus on cards that can mitigate damage. A deck that relies on Heavy Blade doesn’t differ that much mechanically from a deck that relies on Sword Boomerang for instance. Heavy Blade costs 2 energy to play whereas Sword Boomerang costs 1 energy to play, and both cards receive three times the bonus from any additional strength the player has accrued. These can both become big damage cards, and play relatively similarly: gain strength first and then play the card. Now let’s add a relic into the picture: Necronomicon, which makes it so that the first attack in a turn that costs 2 energy or higher is played twice. This adds extra nuance, since now if you play Heavy Blade with a Necronomicon, your big damage card now deals twice the damage, and you may want to hit more question marks on the map to increase the chance of seeing the event when you get this relic from. Relics are capable of separating otherwise repetitive deck compositions from each other. They not only affect how the player plays the cards they currently have within each turn, but can also steer decisions on what new cards to add or remove as well, which applies to both notions of hand optimization and card collection.
I really enjoyed the nuances introduced in this blog post about the tension between control/consistency in what cards you have at a given moment and a constant attempt to improve your deck by adding more powerful cards. I’d like to complicate this idea in the context of Slay the Spire by proposing a rough structure for when the game rewards which kind of play. At the beginning of the game, you start off with a pretty small and very weak deck. Especially at higher Ascension levels where the difficulty is much higher, much of the first act is spent trying to pick up as many playable damage cards as you can, up to a point. This fits into your definition of card collection — the deck we have is very weak and even a middle-low damage card will improve the deck. (After all, very very few attack cards in the game are worse than Strike.) In this early stage of the game, a hand optimization strategy simply doesn’t work. While a Defect deck with 10 default cards and one Electrodymanics might be strong enough to take down any hallway fight and half the elites, the drop rates of the game simply don’t allow you to plan around that strategy.
As you move to the later stages of a run, this strategy will not take you very far. To beat Act 2 bosses or to make much progress in Act 3, you really need to improve the quality of cards in your hand in order to scale over the course of a fight (eg Strength, Poison, or Focus) and play powerful cards in extended fights. You’ll have access to way more powerful cards by now, but if you’ve continued to pick up every decent damage common you see (or failed to remove Strikes or some of those commons you picked up earlier), it might be turn 3 or 5 or 8 before you even see those powerful cards. This is when you need to really make use of the “Skip” option on card reward screens and think very critically before you chose to take a card. There are 50 floors in the game, and discounting Event floors and rest sites but adding in shops, you probably see 30-35 card reward screens over the course of a run. Add 10 starting cards and we could easily have a deck of 45 cards at the end of the run. But some cursory analysis of aggregated StS runs, the average winning deck has about 30 cards (and I think smaller decks than that may have an overall edge, I don’t know the median deck size).
I seem to have rambled a lot about StS strategies in this response, but I think my main point is on the ways you have to shift between card collection and hand optimization as you get farther into the game. That’s definitely one of the reasons that the three Acts have very different feelings from each other, and one way that the game manages to remain fresh for me even after more than 200 hours.