In 2018 I bought a game called Slay the Spire, after lots of people fell in love with its weird art and genre blending. Slay the Spire is a deckbuilding game, meaning you have a deck of cards that you add to and remove from over the course of the game. The game consists of a series of combats, and on each turn you draw cards from the deck you're designing, and choose which ones you want to use. Slay the Spire mixes in a layer of roguelikeyness on top of this, and a little touch of MOBA flavouring, perhaps, as well.

I played Slay the Spire for a little while, enough to beat the game with two of its characters. Something that made the game really fun was what Tom Francis later called its 'juicy maths' - Slay the Spire has numbers on its cards that multiply together with each other, stack on top of one another, and generally layer up and explode as you build a deck. Cards modify costs, stack damage, trigger off other events. It lets you do ridiculous, fun things - but, at first glance, only if the right cards appear. It was frustrating to invest in poison cards, for example, and then fail to find the card that tripled your poison, or die to an unexpected monster that was immune to it. After a few more hours playing, I decided I'd seen what I needed, and I put the game away forever.

Fast forward to today, and in 2021 I put around 250 hours into the game, completing it with every character on all 20 levels of its super-hard Ascension mode. It's one of the best games I've ever played, and it changed a lot of my thinking about probability, strategy and randomness in games.

What changed?

Most of the change comes down to three people. Mark and Mike, friends of mine who are generally good at games that I don't understand at all, starting playing and talking about Slay the Spire a lot as the pandemic set in. Mark had put up some videos explaining how to play one of the characters, and I put it on idly one day while working. Mark's approach to playing and thinking about the game and the choices it offers you was entirely alien to me. Instead of going all in on a big focus, Mark played for balance, looking for smaller, subtler synergies between cards, and flexible strategies that would allow him to play in different ways.

Mark had also recommended a Twitch streamer called Jorbs, who it turns out is probably the best Slay the Spire player in the world. Jorbs runs a very friendly community and has a really relaxed relationship with his viewers, does lovely things like fundraising for charities and supporting good causes and people, and he's also a superb teacher (his bonus video content on mathematics, strategy and games are incredible). Mostly, though, people come to Jorbs to watch him do one thing: play Slay the Spire at an incredibly high level, and make it look easy.

I watched quite a bit of Jorbs' videos, but my favourites were his Overexplained videos where he teaches a character from the game by diving deeply into every decision he makes in a single run of the game (in one of the videos it takes 41 minutes for him to enter the first battle in the game because the analysis and preparation is so in depth and reader? I loved it.) You might think that a lot of the stuff was such overcomplicated, high-level thinking as to be irrelevant to regular players like me. At one point Jorbs pauses to contemplate the exact chance a potion will drop next, which influences his decision to drink a potion now, something I have still never contemplated in 350 hours of the game. But alongside the fine detail and nuance, I found something even more useful in Jorbs' perspective on strategy.

One of Jorbs' other fascinating talents is being a poker player, another game I have often struggled to appreciate and engage with. I love randomness. I have basically dedicated my life to understanding how it affects game design, procedural systems and AI. I love its effect on games in particular because it upends traditional skills and grind, and instead tests improvisation and adaptation. Yet I was also often put off and frustrated by games that seemed to present impossible situations, or upend plans I had made due to something I had no way of foreseeing.

In one of his videos Jorbs responds to a question he gets asked a lot - is every Slay the Spire run winnable? Because Slay the Spire can often feel so brutal, and because randomness does funny things to human brains, a given run can feel so unlucky, so unfortunate, that it seems not even the best player in the world could win it. Other times, a run can seem blessed with such good fortune it could be won blindfolded. The community would eventually answer this question, after a lot of research. But Jorbs explains in the video that he's not especially interested in the answer. Instead, he explains that his only interest when starting a run is to perform as well as he can, to get the best result he can achieve for this particular random run, even if that best result happens to be failure. It didn't matter if any given run was unwinnable - there was always a 'best' performance that could be had, and that was what Jorbs was seeking.

Like all the best revelations, this feels obvious in retrospect. Yet I know that there would be a great temptation, especially among engineers, to think of Slay the Spire's unwinnable scenarios as flaws, to tweak it so every run was winnable, or to see consistent odds as a goal to achieve. Unstanding Jorbs' perspective helped me reassess my relationship with the game, with randomness in general, and also opened me up to think differently about strategy in the presence of randomness, too. Possibility spaces are unpredictable and uneven, but that doesn't need to be a problem, even if you want to play a 'serious' game inside them.

Over time, I learned to understand how Jorbs lived and planned and won in this murky "grey zone" that most of the Slay the Spire landscape consists of. Playing DOTA 2 had taught me how to play extremes, how to min/max, something which I had little understanding of previously - the idea that you invest a lot in some areas and neglect others, getting exponential gains in your strengths and thus beating a balanced approach overall. Min/maxing was something easy for me to understand, because it's reliable and has clear goals. But probability-driven games rarely allow you to get guarantees - at some point you have to step into the realm of 'maybe'. Playing Slay the Spire in 2018, that had felt to me like playing the lottery - in other words, you pick an outcome and hope. But watching Jorbs, and talking to my friends, I began to understand how they all played with intent and purpose, despite having nothing concrete to depend on.

Previously my love of procedural generation was closely linked to the chaos it caused. This was something Tom Francis identified and leant into for Heat Signature - designing a game that forced people into awkward situations to make them improvise. I appreciated roguelikes where it felt like anything could happen for the same reason, it produced interesting scenarios I would otherwise avoid. But I was also terrible at actually beating these games, or even getting better at them.

In late 2020 I returned to Slay the Spire and began to play Ascension mode, starting at Level 1. Each level adds a new modifier to the game - start with less health, shops are more expensive, enemies behave more aggressively - and I learned to adjust my playstyle. Instead of thinking about making my deck good at one thing, I began to balance it around what could happen, instead of what I wanted to happen. I began to accept that anticipating a scenario that ultimately didn't happen - like the chance of encountering a particularly nasty kind of monster - was still sometimes the right thing to have done. You weren't playing based on what did eventually happen, you were playing all possible futures at once. In many ways, it began to feel I was thinking like an AI.

At the end of my Ascension journey, having completed three of the four characters, I started on the home stretch with the fourth and final character, The Watcher. Jorbs didn't have an updated in-depth guide for this character, and nor had my friend Mark made a video, which made it an interesting sort of final exam for me (although she is considered to be the easiest character to break the game with). Going in alone, putting my new knowledge and skills to the test, was immensely satisfying. This game I had put away in 2018 for seemingly unfair randomness was now full of new dimensions, and I was able to build my own sense of this character, what they could do, what subtle choices I could make to bend the game's randomness this way or that.

My last few victories with the character felt like the perfect closing note for my journey with the game. To complete Level 20 of Ascension you must play the game with all prior 19 modifiers applied, and then beat a final boss twice. For other characters, like the Silent, this was so hard that I felt like despite all I had learned I was still waiting for a bit of luck to swing in my favour in order to get the win. But with my final Watcher runs, I would cross the finish line with a deck I never really thought was a safe bet. I never felt like I had a knockout deck, and fights would often be tooth-and-nail, trying to figure out a lateral move I could make to reset or gain some ground. It felt like I'd achieved a meditative level of balance with my decks, where they didn't feel like they did anything in particular, but ultimately were able to do exactly what was needed. I had learned to live and play in the weird murky grey fog of randomness, and it felt amazing.

If you're interested in exploring the fog yourself, Slay the Spire is on Steam, iOS, there's a Switch port, it's everywhere! I highly recommend Jorbs' Twitch and YouTube too, of course. And if you ever want to talk strategies for The Silent, I'm always keen. Thanks for reading!