Ladder Info

Hey guys Burkhart here to talk about an upcoming feature for the game – Ladder. I want to give you an overview of the goals, follow it up by design thoughts and then talk you through the feature

Goals

The goal for the ladder is two-fold. We want to give players a way to play against others in a fair environment. We also wanted to make the system simple in presentation and easy to explain to newer players. In addition to the above two goals, we wanted to reward players for participating in limited tournaments by naturally doing what they are doing in the game: play in drafts and sealed gauntlets. This is a somewhat secondary goal to the above two.

There are a couple of systems that lead to a ladder experience. The first one I want to talk about is the Star Craft II and the League of Legends ladder. In a most basic sense, these use a Match Making Rating and the outcome of matches to determine your rank on the ladder. They are somewhat complex in how they function and intentionally don’t make their internal mechanics well known. This is primarily done to limit system exploitations as being at the top of those ladders has some significant ramifications. The other option for a ladder is a simpler approach like the Hearthstone ladder. This type of ladder focuses on simplifying the experience for the players and make it very easy to explain to new players for how to interact with the ladder. Hearthstone’s ladder gives you stars for winning and takes stars away for losing.

Design

During the design of the system we wanted to check a few assumptions. First we narrowed down our choice between a black-box MMR ladder and an open design. Then, we wanted to set up some checks to ensure that more experienced players are not ruining the fun for less experienced players. With the design we also wanted to make sure that players felt a sense of progression and that players were rewarded for engaging with the systems. Finally we wanted to ensure that if spectators via a live stream observed a ranked match, they could contextually understand the rank of the two players. Finally we wanted to make sure that high skilled players moved up in ranks as quickly as possible to avoid the feel-bad moments of newer players getting outclassed both in skill and in collection size.

After we narrowed down the design and made a few assumptions, we decided to test some of them. We took 6 months worth of past tournament activities for limited tournaments and applied our limited ladder model to them. We wanted to see how many people make it to Cosmic and what sort of spread of players we end up having. Of course, this test was somewhat distorted because players playing in tournaments were incentivized to only play in the tournaments by rewards they received. There were no meta-rewards to keep playing. However, even with the lack of rewards we found that players play a surprisingly large amount of limited tournaments, so it was reasonable to expect quite a few high ranked players.

For constructed, we didn’t quite have the right data in the game, so we built a model. We took a large number of players and randomly assigned them a skill value between zero and one. We then also used similar assumptions to assign players an activity rating. We then had these fake players play against each other for the whole ladder season. We checked the results to ensure that players with high skill level ended up at the top of the ladder with a bias towards those who participated more based on their activity rating.

Once we were satisfied with the test results we went on to implementation.

Outcome

We settled on the following implementations. There are two ladders in the game: one for constructed play and one for limited play. They function similar with the following two exceptions: in limited ladder, you can not drop down in divisions and in limited ladder due to the nature of participation, you do not get paired against similarly ranked opponents.

The ladder consists of 5 divisions: Bronze, Silver, Gold, Platinum and Cosmic. Each division except for Cosmic is split into 5 tiers (V through I). Your division and tier is your rank (i.e. Silver III).

Players progress through ranks by playing matches. Each match win results in a star and each match loss results in a loss of a star. Win streaks are rewarded with additional stars to accelerate players to their “correct” rank. You receive an extra star for winning two matches in a row and two extra stars for winning three matches in a row. Additionally, if you win a match 2-0 you will earn an additional star.

Players are matched against opponents with similar ranks. To avoid delays in matching, if we don’t have an opponent for you with a similar rank, we start widening the search for an opponent.

Bronze division is special. Once you graduate out of Bronze division, you cannot go back down into it for the season. Similarly, once you reach Cosmic division in the season, you can not go back down to Platinum for the season.

Cosmic division ranks the top 100 players in it, but can accommodate any number of players. So for Cosmic, you can be Cosmic 1, Cosmic 2, Cosmic 3 and so on until Cosmic 100. Then anyone after Cosmic 100 is referred to as Cosmic. Cosmic ranks the first 100 players by the internal MMR that we use. All cosmic matchmaking is done using the MMR.

Seasons are slated to last for two months. At the end of the season, players receive sleeve rewards based on their highest ladder rank in the season. Then players’ ranks are reset. High ranked players will gain a small starting bonus at the start of a subsequent season to once again make sure that they aren’t disrupting the play experience for newer players on their way up.

Rewards

Then the big question is: What can you earn by playing in the ladder during its inaugural season?

Sleeves

Each player that participates in the League will have access to a Season 1 Sleeve. You will instantly get access to the sleeve of your rank during the season, and the sleeve will automatically update itself to match your current rank should it change. At the end of the season the sleeve matching your highest rank achieved will be added to your sleeve collection.

Plinth

During the season, players will have their deck pedestal decorated with a plinth of their current rank. This will carry over into all games during the season so your opponents will know just how much to fear you.

Alternate Art Cards

Players can earn two AA cards during each season. In Season 1 those two cards are Arcane Focus AA and Scorch AA. You can earn a play set of these alternate art cards by participating in both Limited and Constructed ladder play.

Gold and Packs

Each time you move up to a new rank you’ll earn something new. Some of the rewards are gold and Primal Dawn packs. You only earn the reward the first time you achieve a new rank.

UI

Let’s look at some of the new UI that will be introduced with the launch of the Ladder:

Tournament Screen

A streamlined interface that allows players to focus on current events and provides contextual information depending on which event they are interested in. At the bottom is the ladder interface that tracks your current ranks for both Limited and Constructed.

Click on the buttons on the shield to get tournament details or participate in an event.

Ladder Interface

This tracks your rank progress and shows you how many stars you currently need to move up in rank. You can toggle it open and shut via the arrow button at the top. You can click on the individual ranks to see the rewards you can earn within those ranks. Leaderboards for both Limited and Constructed are also viewable within this interface.

I want to end this with a gentle reminder: this is Season 1 for the ladder. We will definitely be evaluating the results at the end of Season 1 and throughout the season collecting feedback from players. Please expect that nothing is set in stone with regards to the ladder. With that said, I’ll see you in the cosmic tier!

-Corey Burkhart

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