The Design of Rocket League


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Two weeks ago something unusual happened to my gamer alter-ego. I got hooked on a game. The first time in a long time. Many other poor souls seem to have fallen into the same addicting trap called: Rocket League.

Then my Game-Designer alter-ego jumped in and raised the question why this was so much fun. So of course I needed to investigate and dissect what caused this steamrolling success.

I tried to identify the key pillars that are mainly responsible for the current success of the game.

The Game

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Rocket League is basically football. With Cars. That can fly. And jump. Players control their car in the 3’rd Person view and try to move the ball into the opponents’ goal by bumping it. Although it offers a single-player-mode it heavily focusses on symmetrical PvP gameplay (Team-Competition or 1vs1).

The fundamental gameplay principles are heavily inspired by real sports. As it is a pure competition of skill in a physical environment with physical challenges. There are no exploit progression mechanics built into the game other than players becoming better at the game (similar to other competitive games).

Accessibility

The main point I will dwell on, is how the Developers of the game have designed it to be incredible accessible. While “Accessible” seems like a contradiction for a game with a competitive audience I will lay out how the designers of rocket league have achieved both. Making an incredible competitive and challenging game while everyone is able to pick it up.

Simplicity

The easiest way is to make a game accessible is to make its rules & systems simple. Rocket League’s core gameplay relies on 2 pillars: Input Execution and Tactics. While tactics are added gradually other the course of the game.

The amount of mechanics players can use in Rocket League is negligible, but because they must be combined to use their full potential: there is a huge “Skill-Space” for players to explore.

The game remains interesting as each mechanic takes a significant amount of time to practice until players can use it purposefully. But the time invested will yield diminishing returns in terms of “skill”. A players skills will eventually stop improving at its “natural limit”. The faster a player learns and adapts, the sooner this point will come. The game has them then either hooked them on the tactical layer, or they will get bored because they have exhausted the games systems. And the only way the game stays interesting is through interesting PVP interaction.

Still, Rocket League does an extraordinary job on getting players to that point. A new player can just pick up the game and have fun and score goals with the most fundamental mechanic: Accelerating and Steering. This is a perfect example of  depth & complexity. The game is simple enough to pick up, but then has enough depth that allows players to learn.

Level Design

Although there are some different Maps, they merely differ in their visual and auditory presentation. There are no varying level layouts. Therefore the only key points the player needs to keep in her “spatial”-awareness are the two goals and the fuel-pickups that are also in the same spot on every map. This allows players to focus solely on the ball and tactics (which is challenging enough by itself).

As stated earlier, I believe that these choices were made in order to stay true to the “sports” character of the game. Real life sports rely on the same core pillars: Execution & some layer of tactic. They do not alter the playing field to keep things interesting. It is a contest of pure skill and the ability to “read the game”. Most sports rules are quite simple but have a huge emerging depth from the “input randomness” and different tactics.

 

Core Gameplay

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Each loop is part of a goal hierarchy with the ultimate goal to win the round. In order to win a round, players must score goals and block opponent goal attempts. To achieve this they must gain control of the ball and apply tactics. Goals and core mechanics are strongly tied together (to be expected from a good game, not self-evident though). On the lowest level we have all the movement mechanics (which is basically everything the player can do) is a test of player’s abilities and each test gives players the opportunity to use their skills.

This way, players never truly lose even if they don’t win a match they can find success and recognition for their skills in the small things

And even if they lose, a round – the games longest gameplay-loop – merely being 6 Minutes makes failure less punishing as the time invested is not too high and the next short round is just one click away.

The lack of an in game-economy eliminates potential “kingmaking” mechanics other games would have to fight with negative-feedbackloops. And the short rounds allows the design to make “comebacks” a core element of the games narrative.

 

2 Sources of Fun

There are 2 main Sources of fun: Success and Mastery.

One informs another but they are separated. Fun from Success happens through winning, scoring or otherwise dominating the opponent. The downside of “Fun from success” in a PvP-based game is that the success of the one team is the forfeit of the other team. This is called a zero sum -game. Fortunately, the sum of fun in Rocket League is >0. The reason for that is the “fun from mastery”. Players have the chance to have small successes by using tactics / mechanic-combinations that they have learned by that time. Fun can be experienced in all of the games loops. Additionally the game rewards certain action such as a pass to the center, or a save with points which accumulate to a player’s point-rating at the end of the match.

leaderboard

Another element that makes “Mastery” such a strong motivator in Rocket League is that the Acquired Skill is the actual progression of the game. Yes, the ladder also lets player progress, but this is merely a measurement of the players skills compared to others. And a ladder system implies that a player’s rank can decline. But it is unlikely that the skill of a player declines.

This principle is not unique to Rocket League, if you think about any successful competitive PvP game – player-skill-progression as a main motivator is what they all have in common.

 

Randomness

The Core of Rocket Leagues gameplay lets players interact with physically simulated objects. The car being the avatar with controlled in various ways. And a Sphere. This physically accurate simulated game world is highly chaotic where a slight alternation of inputs, create very different results. Together with rather imprecise player-inputs this opens up the room for many random & and uncertain events. The player is never 100% sure into what results her inputs will end. Of course it is not physically random since the physical simulation is deterministic. But so is the roll of a die in the real world. But by just alternating some of the input parameters (speed, angle, height of throw) we can produce nearly random results. Getting the balance right between random & intended results of physically interacting player controlled objects was probably one of the challenges when polishing Rocket Leagues Gameplay. Having some degree of randomness comes in handy in 3 ways:

  1. This randomness can create lucky moments such as unexpected goals, spectacular saves or otherwise funny and thrilling events which adds a very interesting layer to the games narrative that is otherwise merely constructed by the skill & tactics of the players.
  2. Fairness; The more uncertain the feedback for a particular input is, the more casual/newbie friendly it becomes. This way the game allows also beginners to have some success against opponents at a slightly higher skill level. I think Rocket League hits the sweet spot between Skill & Randomness for their target audience.
  3. Reducing randomness becomes the long-term goal of players on their path to master the game

When advancing, and player are able of hitting the balls more accurate, tactic and strategy become more important as they require a certain amount of mastery to be executed.

 

Matchmaking

All of the previous stated would lead to a total mess if the matchmaking was not near to perfect. Newbies would be crushed by skilled players leading to frustration for both player types. While Pro’s wouldn’t finding meaningful challenge and newbies not finding any success.

Players progress at their own pace in the matchmaking system. They will mostly find a challenging opponent at their skill level. But players can still learn strategies from each other. Which leads to small but continuous skill improvements. The games power curve is controlled through the matchmaking system. It determines how fast players can learn new strategies.

 

Emerging Tactics

One remarkable fact about Rocket Leagues design is that all cars are basically the same. Many games try to introduce tactics & roles by implementing Rock-Paper-Scissor Elements (RTS-Factions)or by Interdepending classes (Team Fortress Classes), or by a complex Counterplay-Systems as in League of Legends.

Not forcing players to pick a role creates freedom but also the necessity to work together as a team more closely. Example: There is no “goalie” car, which is bigger, or can jump quicker. If there was, that player would be doomed to play defensively the whole match. This does not only reduce choices for that player, also the tactical depth of the whole match would be harmed. As reacting quickly to opponents counter-attacks by building a defense quickly becomes less of a challenge.

 

Training Modes

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There are a couple ways players can learn about a certain mechanics (or the way to combine them in order to). They either see another player in multiplayer use it, they find out by experimenting themselves and then there is the training mode. A very nice way to teach players advanced mechanics.

The trick here is that the game never explicitly tells the player how to use the mechanics, instead it puts the player into a specific situation in which there is basically just one solution for the player. E.g. in the goal training the player spawns in the goal and a huge canon shoots the ball into the goals direction. The task is clear, now players need to figure out how to do it. Also the feedback whether they succeeded or not is quite clear.

 

Viewability

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I think one of the reasons for Rocket Leagues current success is that it was picked up by many Streamers on Twich.tv The main reason for that being of course that picked it up because it was simply fun. And increased popularity also increases chance of streamers playing it. So View-ability plays a role in popularity but is not the sole cause.  What makes Rocket League such a good-to-watch game?

  1. The drama mentioned earlier, with an entertaining streaming, the drama created by the gameplay is even enhanced and is entertaining
  2. Easy to understand: Get the ball into the goal there is no research required in order to get into the meta of Rocket League

 

Car Customization

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Players want to differentiate. In a game so heavily depending on symmetric abilities, this individualism must come from elements that don’t affect the gameplay. Rocket League satisfy the players need to show off and underpin their social status by offering a bunch of unlockable customizations for their cars: decals, colors, particle effects and of course hats.

Every time a goal has been shot, the game shows a recap of the last couple of events in slow motion. Since in the otherwise fast paced game details such as the specular mapping for car decals can go by unnoticed, these are the perfect moments for players to show off their car.

Although they are not many ways to customize the cars it is sufficient so that every player can create something unique (And I bet they will add more cars & customizations later)

 

Conclusion

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The best thing about the game, might be what will cause its downfall eventually: Its simplicity.

Player progress until their Skill Plateaus – since there are no other progression mechanics, this is when the game starts to get boring. The only way they can “get something” out of the game is by succeeding and winning matches. Since the matchmaking works quite well players will win maybe half of the time (depending on their skill-level). So a player’s skill ultimately determines how long the game is enjoyable.

By adding more game modes this problem could become less imminent because it would allow players to maybe become good at another game mode instead. So players could find their “niche” that they enjoy.

How do other competitive games solve this problem? – More Content. Mobas add more heroes, CS:GO adds more maps, and StarCraft adds more Units & Builds + More Maps. Adding more content will be difficult in Rocket League because the systems are not built around interesting levels, abilities or units.

This is why I think that adding additional game modes is the way to go (e.g. a Golf Mode, Tennis, or Volleyball etc).

Overall Rocket League is a very tightly designed game with exactly the right mechanics that it needs to be fun and engaging for a competitive core audience.

 

The Heart of Game Systems

In my previous post:  “The Game Design Rabbit Hole” I have conducted my struggles with game design and it being not as a solid craft as I wish it was. This is yet another attempt to shed some light into the dark. And of course, this merely reflects my own opinions and learnings.

In this article, I will flesh out how games work and what makes them so engrossing. To do this, I build my case on the works of Raph Koster’s  “Theory of Fun” And Daniel Cooks’ “Feedback System”.

Fun = Learning

Raph Koster’s “Theory of Fun” is that the source of all fun is learning. Confronting the player with a challenge and giving her the capabilities to overcome it. It’s a task for the brain to figure out through an iterative process in which players refine their strategies up to the point where they are able to overcome the opposed obstacle. I want to dive into that a bit more and share my thought on how exactly this approach can help to take apart the process of designing games into more tangible pieces.

The Game -Loop

*This is not a merely decorative image. Take a closer look as this is what this text is about :)

*This is not a merely decorative image. Take a closer look as this is what this text is about :)

 

The player and the game are communicating with each other. The player speaks the “language” of input and the game answers with “feedback”. Players then form a mental model of the game system and the inner working of its parts. Through Inputs, they can modify parts of that system. The game will then alternate its current state and communicate that change to the player. These Inputs can be intentional, if the player has already learned what the resulting state change can be, or experimental if the player is still figuring out that part of the game. Either way, the feedback system will inform the player about the impact of these inputs and the player can validate it. Even more importantly, the players gain knowledge about how the game-system works and can in turn, update her understanding of the game-system. The intention is informed by goals which either emerge intrinsically in the players mind, or the game can explicitly give these goals extrinsically. More extrinsic goals are better for the early game when players still need assistance in learning the basics of the game. Extrinsic goals, if rewarded properly, will align with intrinsic goals eventually. “Reaching level 90” in an RPG is an extrinsic goal, while “I want to become more powerful” is an intrinsic goal. Ideally, they match, but first players have to learn that leveling up makes them more powerful. With that, the next loop of the feedback cycle starts. Every iteration of that cycle is an opportunity for players to learn. If the players knowledge of the games system has been established well enough (by running the feedback loop a sufficient number of times) the inputs players make can become intentional towards the desired game-state. The “desired game-state” can be an explicit goal stated within the game (e.g. finish a level) or a player-internal goal (I want to build a nice city). Throughout a game, the players understanding of the increases and a well-paced game will alternate between applying and learning strategies.

Strategies & Goals

I use the word strategy very broadly in this text and it means the following:

“A strategy is the intentional alternation of the game state through a sequence of inputs that lead to a desired state”.

 

The “desired game state” implies an intention on the player’s side. She wants the game to do something specific, so she uses her knowledge of the game to manipulate it. It is somewhat related to what Daniel Cook describes as “Skill Atom”. Although a “strategy” in this text can describe the usage of multiple “Skill Atoms” to achieve a particular result within the game world.

This definition can be applied to all levels of a game system. From a simple mechanics e.g.

  • Press the jump- button at the right velocity & position to perform a jump collect a pickup in Platformers
  • Placing units behind cover so they receive less damage in XCOM, spread units to mitigate Alien-AoE Damage
  • Throw a smoke grenade into a tunnel to deny an enemy rush in Counterstrike
  • Only shoot in small burst to maintain accuracy (FPS with recoil mechanic)
  • Place an observer at the enemy base to gain high ground vision ( Starcraft 2)
  • Find the biggest match in order to get the biggest possible cascading effect (Candy Crush)
  • Deploy skeletons first when attacking an enemy base (Clash of Clans)
  • Spend all of the mana in a turn in Hearthstone
  • Defending enemy attacks in a Beat’em’up
  • Execute headshots for increased damage
  • Stock up on pokeballs before leaving a town

To more complex ones– these strategies require a deep understanding of a games systems and require some iterations of the feedback cycle before they have been formed and mastered

  • Find efficient city layouts to maximize population happiness and thereby tax income
  • Min-Maxing Character stats in an MMO
  • Building a deck in Hearthstone around a new card
  • Using certain attacks to force the opponent into a bad position and then exploit that weakness with a finishing move/combo
  • Only pick up the most valuable goods in “This war of Mine’s” scavenging mode

The skill a player uses to execute a strategy varies greatly from genre to genre. Executing a headshot requires accurate mouse movement & reaction time while placing buildings efficiently requires strategic thinking. Both are strategies that work towards a goal in the context of their game. The applicability of this model to almost all genres makes it such a powerful. Learning strategies and combining them is what makes games entertaining and what keeps them challenging – given that the game provides more complex goals and deeper systems to interact with. A game becomes boring when there is nothing new to learn, or there is no incentive to combine learned strategies to reach more complex goals. This can be achieved by either increasing the depth or the complexity of the mechanics. Players attempt a solution of the goal with a certain strategy. The game will inform the player whether the attempt was successful or not. This iterative process how learning works and is engraved into the human brains by rewarding its success. When it comes to difficulty I consider creating challenges that gives players the opportunity to show how smart they are rather than showing them that they are inadequate. I think this is exactly where the border between challenging and punishing difficulty lies, but that is a totally different topic in itself.

Actionable: “Look at the mechanics of your game and list possible strategies. Map these strategies to possible explicit and implicit goals. Validate whether all strategies are tested by the goals and whether some your mechanics are underrepresented in your strategies.”

In the players Mind

The player’s ability to act inside of the game context hinges on 3 aspects:

  • Understanding the System: How much of the games system has been understood
  • Understanding the Inputs: To what extent is the player aware of all the possibilities she has to interact with game-systems (not the physical inputs)
  • Transmuting: Combining system-knowledge and input-knowledge to create a hypothesis about a new strategy: “I wonder if I can avoid taking damage by jumping over that enemy”, depending on the target audience this part is either left to the player through experimenting or has to be explained explicitly
  • Applying: Ability to use acquired strategies to solve the games challenge

This perspective allows to break down “player skill” into more tangible parts that can be addressed individually. Especially the first 2 are directly under the control of the designers through good tutorials and an elegant pacing of introducing new game elements and systems.

The latter two are not in the direct control of the designers are they happen mostly in the players mind, but with proper guidance (e.g. highlighting vulnerable parts in a boss-fight) we can assist players in finding solutions. Games test the “Transmute” and “Apply” categories with the goals they present to the players. When a player solves a challenge, she has proven that she has mastered the strategies associated with that goal.

Actionable 1: “Understand how your games performs in teaching the systems (through feedback) and the inputs (possibly through tutorials). Ensure that the challenge matches the player’s abilities to transmute & apply (Flow). “

Actionable 2: “What strategies do you teach explicitly and which ones do you leave for the player to discover? Discovering new strategies is one of the most rewarding moments in a game, but leaving the player too helpless can lead to frustration.”

The Hook: Player Agency – Rewarding Curiosity

Players invest upfront into a game by buying, downloading and launching it. So the game starts with a small debt towards the player. We know what the player want in general (“A nice experience”). So it should be the games’ first task to repay that debt and give players something in return. The more we know about the target audience for a certain game, the more accurate we can deliver that. Introducing the players to the core principles of the game and letting her execute that and yield first successes (as in ascertaining the games systems by experiencing the feedback-loop) will hook the players and motivate them to further explore the game. How do we do that? We show them that their inputs have an impact and lay out breadcrumbs for players to discover and figure out. These breadcrumbs can be a piece of narration about the world, a new ability, a new enemy. Everything that rewards curiosity or that introduces new elements keeps the players interested. This spiral goes on as long as the game actually makes the effort to encourage the players’ curiosity. At no point, the game becomes a “no brainer”. The game always needs to promote progression.

Empowering players through learning and applying the knowledge/skills, conveys a sense of accomplishment and mastery which ultimately is the core of a game experience and is what hooks a player.
Games provide an obstacle (be it a QT in a “walking simulator” or a boss fight in Dark Souls), but also the tools to solve them. Beating a challenge is already rewarding in itself intrinsically. If the player has reached the intended game state by using the abilities the game has taught her she has a feeling of agency and power within the game world.

narrative exploration vs bossfights

The concept of player agency applies to narrative exploration in the same matter as to boss fights.

Despite the resentments from core gamers and even some stubborn game designers, “Heavy Rain” just works like “Dark Souls” in terms of player agency, Players are in control of the games system an progress through the game-world on behalf of their intentions and the resulting actions. And that progress is communicated through whatever extrinsic rewards the particular genre has to offer. A cut-scene (narrative reward), a level-up (power reward), a new level (content reward) etc.

Actionable: “Is the feedback for the mechanics clear enough so that the player know what consequences their actions have? Carefully consider what events in the game world are tied to the players input and what are systematically generated (e.g. by randomness)”

Conclusion

Many things in this article were “stating the obvious” for most designers out there. But my approach to these articles is more of a “What would I have liked to have known when I started designing Games”? I hope that this approach of dissecting the individual parts of the game experience will help to single out certain design challenges that we face along the way of creating awesome games.

My belief is, that the better I understand how games work and what drives players, the better I can “design” systems that fulfill a certain purpose: Bringing fun to players

PS: While writing this post, I discovered the video of a presentation about “Defining Gameplay: Between structure and chaos” that industry veteran Alexandre Mandryka (Ubisoft) was giving. It pretty much sums up everything that I wanted to say here and is a must see for any aspiring game designer IMO.

Rabbit Hole: Game Design

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The process of designing “fun” has always been and is still is an undefined matter for me. All the books, all the articles, all the thoughts expressed on how we designers should approach this task just left me with even more questions than before. I became to realize that there hardly is a common understanding of our craft. Though I don’t believe that good games are just happening by accident or good processes (such as iterative design & prototyping). There seems to be some truth that every successful designer has his or her version of.

There are plenty of ideas and concepts on how to view the player, how to define the interactions between players and the game, what a game is, what a game needs, what makes a game fun. Checklists, lenses, models as plenty as there are designers. I believe, eventually a game designer will end up with its very own and unique variant on how to design games and how they work. But where would I start? How would I become one of those designers who seems to understand how all the elements come together, crafting an experience that is enjoyable for others.

Prototyping

iterative design 1

Prototyping! That must be the way. And there is no doubt about prototyping teaching loads of valuable lessons about _finding_ fun.  Cranking out prototypes, iterating their design and testing them is one of the best ways to unveil the inner workings of games. It will teach about what lets fun emerge, not so much about why it emerges though. The fact that we must rely on prototyping, a trial and error approach, tells me, that we still have a long road ahead of us to bring together those two domains. Sharpening the design skills will reduce the amount of iterations a designer needs to get from A to B and there will be less “failures”, although each failed iteration is the chance to learn something new. I believe that by learning and understanding more of our craft, we can speed up this process and make it more efficient – simply by avoiding mistakes.

Trying to Improve my Skills

I had my own experiences from playing games. At least I knew what fun is for me or could try to tell why certain things where not. In addition I could dwell on the shared thoughts of more experienced designers and people who have walked the same path that I am was about to pursue. I wanted to stand on the shoulders of giants.

shoulders of giants

Since I had already played a lot of games, and read a lot on the subject, my goal was to absorb all the different ideas expressed by other designers and researchers. Then I would reflect upon them by applying them on my own experiences when playing games. In the hope of eventually building up my own understanding of the elements and their arrangement to create “fun”- games (I would like to apply them also to other people’s experiences but that is rather hard unfortunately).

Underneath there is one terrifying fear of which which I don’t know whether other game designers share it: What justifies me earning money from something that I can barely grasp?

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Daniel Cook has expressed an analogy that I appreciate very much – comparing today’s game designers to alchemist in the days before there was chemistry ( The Chemistry of Game Design). Experimenting with the known elements in order to create something new, making up their own version of the truth without knowing the underlying rules. Eventually alchemy developed into an actual science. I would not give any money to an alchemist for creating gold from common materials, would you? Game design as it appears, is not yet at the stage of science. However, it has already left the field of a mere art form. It is something in between. And that, to be honest, makes me uncomfortable by itself. I would like to figure it out. As I will probably not be the one to discover the truth™, I will have to just try my best to find at least some degree of certainty that allows me to ask for a salary. Oh yes, and if you want, you can read about my very own personal discoveries as I write about them.

I will keep you posted.