It’s sometimes difficult to tell the story of how something was designed, especially when there are a lot of moving pieces. It’s rarely a straightforward journey from point A to point B. You start with one set of ideas, but these sometimes shift as you discover something unexpected that demands more support, or when a solution to one problem offers a new path towards another. Legends of Runeterra’s design process is one of rapid prototyping and testing ideas early, starting first from core design pillars. We then shift our focus to champions and deck strategies, then to cards and mechanics, and finally to balance and polish.

All of this design work needs to be guided by a strong, central vision. For Targon, the team laid out our design pillars very early, informed by the themes of Targon and the champion roster: cosmic power, day and night, and the journey up the mountain. The challenge for the design was figuring out how to translate these into cards and other gameplay experiences—and across not one, but three expansions.

In this article, we’re going to take a look at how we developed the core gameplay identity of Targon, and how the first expansion for Call of the Mountain introduces it with various cards. We’ll also look at how champions from other regions bring their own crew to support Targon’s gameplay and give you an idea of how it will evolve in the next two expansions. And lastly, we’ve packed in some anecdotes from the design process we hope you enjoy reading about.

Let’s head up the mountain!

Invoking Cosmic Power with Celestials

The highest peak of Mount Targon serves as a gate to the Celestial realm, said to be the home of Aspects who are abstract and beyond mortal comprehension. This flavor is key to Targon and its champions, so we knew we had to find a way to represent this cosmic power and divine aid from the stars.

In the early stages of design, we do a lot of our testing in the paper—cards hastily are written out so we can try ideas quickly, without investing in coding strange new abilities. During this time, we explored a few mechanics in the cosmic power vein—space gods that required spending multiple rounds worth of mana to summon, and aspects that possessed your existing units. Eventually, it was a deceptively simple idea from Mark “G-Major” Sassenrath that played the best.

He proposed Celestials shouldn’t be cards that could go in your deck, but instead, be a special pool of cards that could only be summoned inconsistently through other actions. This led to the Invoke mechanic, nicknamed “Divinate” initially. With Celestial cards existing outside your deck, they could be stronger than comparably costed collectible cards within your deck, because the cost would be budgeted into the price of the Invoke. This would make the Celestial cards feel powerful and serve our design goal of variety, while also rewarding skillful play and fitting thematically into the unknowability and capriciousness of the cosmos.

When it came to the Celestial cards themselves, we quickly latched onto the overall shape: each cost from 0-10 mana would have both a unit and a spell. Mechanically, this served variety, kept the cards relevant throughout the game, and made the mechanic valuable to different decks in different ways. An aggressive deck could Invoke early to set up Nightfall activations, while a more midrange deck might Invoke for removal or cards to help close out a game. Flavorful, having so many Celestials offered a cosmic hierarchy that could simultaneously contain an adorable puppy constellation and a terrifying stellar Baron Nashor.

Keeping the mechanic relevant at multiple costs would also prove to be the trickiest part to balance. Throughout the design, we had a constant see-sawing back and forth. First, the early cards were too strong and no one would ever pick the expensive Celestials; then we’d balance them and the expensive Celestials would be game-breaking, and people would stop including win conditions in their decks. It went back and forth for months. We discussed some radical solutions like not letting players pick expensive Celestials unless they had invoked a certain number of times, making the powerful end game options only available to players with dedicated Invoke decks. I was nervous about a solution that layered more complexity onto a system that already had a high knowledge burden. But eventually, Xian “Riot Xaenya” Li would address this balance challenge with an elegant solution, giving expensive Celestials more power based on how many Celestial cards you’d played. This way anyone could take them, but it would only be the dedicated Invoke deck that could unlock their full power.

The Center of the Universe: Aurelion Sol

That’s the story of Invoke as a mechanic, but let’s back up and get Aurelion Sol into the picture.

Aurelion Sol was a champion that I knew I wanted in this set from the beginning. Partly it was the strong visuals and concept—a cosmic space dragon with an enormous personality—but I also knew that the nature of a card game gave us an opportunity to do something League of Legends couldn’t. League needs to put every champion on roughly even footing, so even Teemo has to be able to directly compete with Aurelion Sol. But LoR doesn’t need to do that. We have cost (and level up conditions) to distinguish the power of champions.So in LoR, Teemo can be an efficient, exciting card on round 1, while we can make Aurelion Sol a game-dominating 10 mana card and truly deliver his godlike majesty.

Once the Invoke mechanic was in place, ASol’s general shape followed—he would Invoke and he would make Celestials; he would have Spell Shield to help protect your enormous investment; he would require immense power from you to level up, and his level 2 would be as over-the-top powerful as we could make it. There are cards that take many iterations to get right, but we had the rough shape of the Star Forger from fairly early in design.

Matching Cosmic Might with Trolls

When adding a champion to a set, we like to look at the mechanical and thematic hooks that could connect them to other champions, particularly those in other regions. We ideally want a deck for every 2-region pairing, so look for both natural pairings as well as where we need to work to seed in connections.

With Aurelion Sol so expensive and Invoke potentially so mana hungry, we knew he would naturally pair with Freljord for its ramp cards, but it wasn’t immediately obvious which Freljord champ we should choose. Initially, we were excited by Trundle’s ice pillar as a potential stall tool that might offer sideways support to ASol in a slow deck. But unlike ASol, Trundle took a LOT of iterations to figure out and would evolve considerably from our first drafts.

At different points, Trundle and his trolls cared about 0 power (rewarding cards like Faces of the Old Ones and Frostbite effects), regeneration (rewarding Avalanche and Challenger), and even generating lots of mini Wyrding Stones, but he never clicked into place, especially as something you might consider playing in the same deck as ASol. Dave Guskin would solve this, asking “What if he just wanted you to play really expensive cards?” This would lead directly to using “if you Behold an 8+ cost card” and the notion of trolls worshipping the mighty. Everything clicked into place from there. The trolls had a unique identity that fits with Freljord and could connect with a lot of potential decks, including the mana hungry ones in Targon, and we could design a Trundle that was true to his League persona as a giant, bullying brute.

This is one of those places where I get nervous pulling back the curtain because it’s possible no one will want to play Trundle in the same deck as Aurelion Sol. The reality is that’s perfectly fine and fits within our goals. As designers, we care most that the game supports a high variety of different decks with different playstyles, that every champion card feels thematic to the champion character, and that they all have a home in a deck. To achieve this, we seed in certain mechanical connections. For some strategies and champs, we think it’s valuable for these to be loud and obvious (like playing Diana and Nocturne together for the shared Nightfall synergies). Other times, it will be subtle or open-ended. In these cases, we’ve explored potential decks internally, but know that we can’t match the collective brainpower of players. That’s even more exciting! As long as we’ve built sturdy enough tools, players will surprise us and there’s no more satisfying feeling than that as a designer.

The Cycle of Day and Night

The human inhabitants of the mountain are a people known as the Rakkor. Most are sun-worshippers, but there is a secret heretic sect of moon worshippers. To put it mildly, the two groups do not get along. Editor’s note: Shawn’s characterization of the noble Lunari as “heretics” is his own opinion and does not reflect that of the entire LoR dev team.

This duality—day and night, sun and moon, Solari and Lunari—is the essential conflict of the people of Targon and something we knew we needed to reflect in the cards.

We explored a LOT of angles, particularly around the notion that the whole game would shift between a state of day and night, either automatically every other round or as you played cards that changed the time of day. These mechanics proved really interesting, but ONLY when both players were using them and on opposite sides—a day deck vs a night deck in a tug of war over the sky. We explored ways to get non-day/night decks to engage in the cycle, but it pulled so much focus that we reframed and tried to isolate the mechanics to rewarding actions a player could control.

Noah “Riot DefaultChar” Selzer proposed the mechanics that became Daybreak and Nightfall. Daybreak would reward the first play of the round and Nightfall every card after it. We thought this was perfect—not only did it succeed as a reflection of the Targonian conflict, but each mechanic gave its cards a unique quality. Day was deliberate, in your face, and unsubtle, while night rewarded waiting and careful setup through banking mana, only to unleash a big round where you might play multiple Nightfall cards in a flurry. Plus, I liked that the mechanics were open-ended and could be used in any deck (and could even complement one another), but we could also create “build around cards” like Leona and Diana or Rahvun and Duskrider that would encourage you to play dedicated Day or Night decks.

Embracing the Darkness

The Solari and Lunari are deeply connected to Targon, but, as mentioned with Trundle, we like to find those cross-champion/cross-region mechanical connections where possible, so we searched for who else might play into these themes of sun/moon, day/night, light/dark. Nocturne stood out with his penchant for casting Summoner’s Rift into darkness and fit the Nightfall pattern of lying in wait only to spring suddenly on you.

With a champion like Nocturne who doesn’t have a specific region connection, we try to find a home that makes sense either thematically or mechanically (and ideally both). Thematically, we liked Nightfall in Shadow Isles with its literal connections to shadow and darkness, but we also had a nice base of aggressive Shadow Isles cards that could complement the mechanic. Typically, Nightfall rewards early rounds spent banking mana, getting ready, then springing cards on you in a single round. We knew this could have an almost horror movie feel and allowed the team to build out creatures that jumped out of the shadows (or even were composed of shadow), a nice contrast to stealthy Lunari assassins.

The Journey Up the Mountain

Mount Targon is itself a crucible—a towering, impossibly tall mountain that calls to travelers who dare to ascend it. It is a journey and a physical trial that rewards strength and allies who have your back.

This design pillar wouldn’t inspire a keyword in the same way as the other pillars (Shawn looks around, leans in, and whispers: at least not one I can talk about for this release), but it did lead us to consider the suite of abilities that would define Targon’s region identity. We asked ourselves: Which mechanics and champions could play into this journey motif?

Simultaneous to exploring the design pillars, as we introduce a new region, we consider the needs of its full roster of champions—are there common mechanics we should make sure the region contains? This includes considering champions that we won’t introduce until future releases. In the case of Targon, it stood out that the region has a relatively high number of support champs.

Leaning into LoR’s support mechanic itself would imply certain other needs for the region’s cards. Supports obviously protect or buff your units, so it would require units that wanted to be protected or buffed (such as those with keywords like Overwhelm) and also would require tools to protect your supports so they wouldn’t always die on the attack.

Thematically, this fits the journey motif beautifully: Weak heroes begin the journey, but through cooperation and hardship they grow stronger until they reach the top of the mountain (and end of the game) as powerful heroes.

Mechanically, though, it turned out that having a lot of support units could be problematic. First, the mechanic rewards offense, making them terrible on defensive rounds. We solved this by making Targon’s support bonuses permanent. Now if you are able to attack, you’ll be stronger and more able to block. This also made their support units naturally powerful in a long game, and fit Targon’s spells leaning more on “grant” type buffs. Second, sequencing your attack can become very challenging when you have a lot of support units. We tried to address this at both ends, having obvious targets (you see this the loudest in the second support region, Ionia, with cards like Flower Child) and having cards that encourage you to sequence them in a certain way (such as Mountain Sojourners).

Unlike Aurelion Sol, Leona, and Diana, it wasn’t immediately obvious that Taric needed to be in Call of the Mountain, but when we considered the theme of journeying, the support mechanic, and a region defined in part by buffs, he became the natural choice to fill out the roster. We were especially excited that his followers in particular could tell the tale of journeying up the mountain.

More Support With Lulu and Friends

I’ll be honest with you: when I wrote the first draft of this article, I didn’t mention Lulu. It wasn’t that I forgot her but simply didn’t have any particular stories to tell, mostly because she fit so neatly into all our work on the set. We chose her initially to build out the support themes and because we liked the contrast she provided to some of the more serious themes of the set. Her League abilities translated really well into card mechanics and her support cards mostly struck a balance of being open-ended, while also playing nicely together. The main challenges were that, in their final versions, Lulu and Taric didn’t necessarily want to go in the same deck, but as I mentioned with Trundle, that was hardly a problem. They both had decks that were really excited to play them, and we even added a few extra support cards to Ionia (Pix and Fuzzy Caretaker) to round things out, but, all told, Lulu and friends saw the least iteration among cards in the set. Sometimes you get lucky and get more time to devote to designing space dragons.

The Climb Continues

So that’s how we ended up with the mechanics and champions in the first expansion for Call of the Mountain. But that’s just the first of three, and the next two need to continue fleshing out the gameplay identity of Targon.

We’re designing Targon and the Call of the Mountain set as a whole, which means there are more pieces to the gameplay puzzle coming in the following expansions. There are some aspects of the region identity we haven’t even touched on yet and will bring with them new cards/keywords. Others, like Dragons or healing, are present already but could use additional support to really make the strategy shine. Additionally, our hope is that the introduction of these new twists on Targon’s gameplay keeps the meta feeling fresh throughout the entire set.

That’s All, Folks

Thanks for reading through this and letting me share our experience in designing Call of the Mountain! We hope you love the expansion, and can’t wait to see what strategies you discover on your way to the top of Targon.