How Synergies Make Slay the Spire Fun

Hey. Mark here. Over the past few weeks, I’ve been obsessed with a card-battling roguelike called Slay the Spire. Here’s how it works. You start the game with a tiny deck of super simple cards. There’s a few that do damage to enemies, and a few that protect you from incoming attacks. But whenever you beat an enemy, you get to pick from one of three random cards to insert into your deck. You can also gain cards during random events, and buy them from a shop.

And soon enough, you’ll start finding cards that are a bit more involved than simply attacking or defending. There are cards about status effects like poison, strength, and weakness. Cards that have both advantages and drawbacks. And cards that indicate more in-depth strategies. And soon after that, you’ll start to discover cards that suggest using them in tandem with others. This is a synergy, which is when two or more elements combine to produce a more powerful effect than the sum of the individual elements.

And I think this is the secret that makes Slay the Spire so darn good. Lemme give you an example. This is Body Slam, which is a card that deals damage equal to your current level of block. Immediately, an idea starts to form. Other cards, like Entrench (which doubles your block), and Barricade (which stops your block from resetting to zero at the end of your turn), feel like natural partners to Body Slam. If only you could build up huge amounts of block, you could then also deal huge amounts of damage.

Here’s another one. You can increase your strength in Slay the Spire, and this boosts the damage of your attacks. And then there’s this card: Heavy Blade. This one takes the value of strength three times - or five times if the card is upgraded. Pair that up with cards like Inflame (which gives you strength), and Limit Break, (which doubles your strength), and that’s going to turn Heavy Blade into an unstoppable super weapon.

Cards get even more powerful when paired with Relics, which are passive items that constantly give you additional boosts and bonuses. Anchor starts each combat with 10 block, and Red Skull gives you three strength if your health drops below 50% - handy additions to those synergies. And that’s just the basic bloke: the Ironclad. Even more synergies can be found with The Silent, who poisons her enemies. Or the Defect, who juggles powerful orbs that cast spells.

So check out this Silent Deck I made, which is built around these shiv cards that cost no energy to unleash, but exhaust (or disappear forever) when they’re played. So I had one relic that made zero-cost cards do more damage. Another that added a random card into my hand, whenever a card was exhausted. And another that meant I didn’t discard my hand at the end of a turn, so after a few turns I’d have the maximum 10 cards to play with.

Then I had a card called Storm of Steel that replaces every card in my hand with an upgraded shiv. This meant that I could turn my entire deck into nine cards that dealt nine damage each, dealing 81 damage in one fell swoop. But each time a shiv was exhausted, a random card would appear, giving me even more options like defence, more attacks, and so on. This made even the biggest enemies an absolute pushover. And that’s the first, and most obvious reason why synergies are so cool: they make you feel immensely powerful.

In a game where you’re usually just doing small amounts of damage to an enemy, it feels utterly thrilling to do a massive combinatorial attack. But the second reason is that synergies make you feel smart - precisely because you find these combinations yourself. You weren’t simply given the tools to be powerful - you found them. You noticed some link between two cards and put them together in your deck. This way, you can almost feel like you got one over on the developer.

Like you found some illicit combination that gave you way too much power and broke the game. And maybe… sometimes that’s true! But for the most part, the devs planned this all along. They just want you to feel like you figured this out for yourself - to give you that feeling of being a master tactician. And reason three is that synergies are great at adding depth and complexity to a game, but with fewer moving parts.

Because look: if a game has 20 unique cards that only work by themselves, that’s 20 cards for the player to wrap their head around - for only 20 different strategies. But if a game has 10 cards and they can work together, that’s half as many cards to learn, but 100 different strategies! And this allows for what Magic the Gathering designer Mark Rosewater calls “lenticular design”. On the surface, these cards seem very simple and easy-to-use.

Perfect for new players. But these cards also hide untold complexity, that is only seen by advanced players, because the only way to really get the most out of them is to use them in combination with other cards. So synergies make players feel powerful, let them feel smart, and sneakily increase the depth of a game. Sounds like they’re worth putting in more games, right? But they’re tricky to do well. So we have to look at Slay the Spire more closely to see exactly what makes those synergies work.

And the main thing, I think, is that using synergies requires a certain amount of planning. A synergy that comes together too easily isn’t quite as fun as one that requires a bit of set-up. A sort of “oh you’re gonna die sucker - just as soon as I set-up an absurdly complex and unlikely sequence of events!” And this planning happens on multiple fronts: per turn, per combat, and run. Per turn is easiest and most common - it happens every couple minutes.

It’s simply about playing cards in the right order - maybe making an enemy vulnerable before dealing damage. Per combat is a bit more tricky. This is often about taking a few turns to set up a perfect play. Maybe you need to boost an enemy’s poison for a few turns, before hitting them with the card that triples their poison level. Maybe you need to use a card that gives you more energy to spend in a future turn. Or perhaps you need to get two or more combinatorial cards into your hand at the same time, using strategic cards like Setup and Thinking Ahead.

And then there’s per run. That’s all about picking the right cards, making smart choices in the shop, and choosing the best relics. And that’s not to mention that synergies encourage a smaller deck. You don’t want loads of junk cards and curses in your hand - just the cards that feed into your synergistic strategies. So part of the game is about getting rid of cards - either at the shop, or during certain special events.

Slay the Spire makes skipping cards, or outright getting rid of them, just as important as adding them to your deck. That’s so clever. But it’s really important to note that Slay the Spire’s synergies work so well, because of the fact that it’s a roguelike - a genre, like I’ve mentioned before, which comes with a couple important criteria: permadeath and random generation. Random generation means you can’t just pick the perfect synergies from a list - you’ve got to respond to what the game gives you.

In Slay the Spire, you’ll often find yourself building a deck around whatever cards and relics appear early on. You’ve got to think on your feet, and find connections where you can. This also adds to the compulsive nature of the game. There’s this feeling that maybe this run, you’ll stumble onto a perfect synergy. Whether this is addiction or engagement… I’m not sure. Permadeath is also important because synergies can easily turn into optimal strategies - which are tactics that are so much more effective than anything else, that you might as well just do them over and over again.

And after a while, this starts to get a bit boring. But the fact that you’re constantly starting from scratch in Slay the Spire - either because you died, or because you won and you’re now trying a new character or a higher difficulty level - this doesn’t ruin the balance forever. Even my awesome shiv deck was toppled by the Time Eater boss, and I’ve never run into the same combination of cards and relics since. So I think that’s why we often see synergies in roguelikes, like Dead Cells.

In this game weapons, traps, and grenades can cause status effects like freezing, burning, or poison. And then, other weapons can cause increased damage against enemies who are frozen, burnt, or poisoned. The result is attacks that do ridiculous damage. Elite enemies and hordes of foes defeated in a delicious one-two punch where you throw an icy grenade to freeze everyone in proximity, and then slash them to bits with your sword that deals double damage to frozen enemies.

And Into the Breach has great synergies as well. Here, one unit can chain electric shock damage through adjacent targets. That pairs wonderfully with a character that can grapple enemies to move them about the map. But synergies can appear in other types of games too - the combination between the Medic and the Heavy in Team Fortress 2. Clever set-ups in an RPG. And, of course, I probably would have discovered the addictive thrill of synergies much sooner if I was more of a card game player.

They’re at the beating heart of what makes deck-building collectable card games like Magic and Hearthstone feel so fun. But I never normally play these games because I find the deck building aspect so overwhelming. I’ve got to pick from hundreds of cards to make a deck that’s powerful, balanced, and energy efficient? Yeesh, too much for me. But that’s the joy of Slay the Spire - you piece together your arsenal of cards over the course of the game, one at a time.

Making it way less daunting to build a deck, and effortless to stumble upon the compulsive thrill of synergies. Hey, thanks for watching. I had to make a video on this game I've been playing it obsessively and I just had to make a video to get some closure on it and move on with my life. Have you ever played a game that gave you that thrill of finding and exploiting synergies? Lemme know in the comments below.