Everything I Know About Game Design I Learned from Super Mario Bros.
This essay was written for the Well Played project, and is included in the Well Played 1.0 book, which you can read online for free or buy a physical copy on Amazon.com.
Introduction
Super Mario Bros. changed my life. From the moment I laid eyes on the game until… well… right this minute, I've been obsessed with this fat little plumber and his bottomless-pit-jumping, fireball-tossing adventures. No other game has inspired me to spend so many hours playing, watching, reading, writing, and drawing… not to mention the countless thumb blisters. Some of this is due to the time and place that I first encountered Super Mario Bros. - I was of an impressionable age with copious amounts of free time and an unlimited supply of graph paper. But a great deal more is due to the fact that Super Mario Bros. is one of the greatest games ever created.
Super Mario Bros. has been one of the most inspirational games not only to me as a game player and game designer, but also as a game design instructor. I find myself often coming back to Nintendo and Miyamoto's early games as points of reference and sources of solutions for seemingly complicated design problems. Few core concepts in game design were overlooked in this seminal work, and for its time and the technology that was available, Super Mario Bros. is an extremely well rounded game. It should come as no surprise that the original 1985 game can serve as a summation of game design, since it was the practical design template for videogames at large for over a decade.
Even if my students aren't old enough to have had Mario make an impression on them in his 2D glory-days, they are still familiar with his 3D exploits, and the concepts that I'm about to discuss have only been improved and expanded on in Mario's numerous sequels, side-adventures and spin-offs. These patterns are not at all limited to Mario games or platformer games, and can be found in most, if not all, videogames. So now, without further ado, is my practical understanding of game design as viewed through the lens of Super Mario Bros.
Overview
Super Mario Bros. is an action-adventure videogame originally released in 1985 for Nintendo's Famicom and Nintendo Entertainment System brand home videogame consoles. In modern genre lingo, we refer to the game as a side-scrolling platformer. The player takes on the role of Mario, a mustachioed Italian-American plumber dressed in trademark red overalls and matching cap. Mario is magically transported to the fantastical world of the Mushroom Kingdom, where he must rescue the kidnapped Princess Toadstool from the clutches of the evil King Koopa. Between Mario and King Koopa are eight trap-filled "worlds" and Koopa's army - composed of anthropomorphic animals, plants and mushrooms. As Mario, the player must run, jump, duck, and swim through thirty-two levels to defeat King Koopa, save the princess and "win" the game.
Give the Player Clear Objectives
When someone sits down with a new game, be it a board game, a word game in the newspaper, or videogame, his first question is always "ok, what am I trying to do here?" The player's objective is quite possibly the single most important piece of information he needs to play the game and have fun. Every decision he makes will be run through the filter of "does this help me achieve my objective or not?" So as game designers we have to answer this question quickly and clearly. And if the game is of a more open nature, we still need to tell the player that he can select or make up his own objectives.
In most arcade and home videogames of the 1980s, the backstory and setup was something of an afterthought. Some scrolling text that appeared in the game's "attract mode", or a paragraph of seemingly unrelated text printed in the game's manual described some events that remotely resembled what was happening on screen. And Super Mario Bros. is no exception. We can look at Super Mario Bros.' objective two ways: either as the first-time player who has just picked up the controller, or as the player that's read the manual or is already familiar with the mythos of the Mario universe.
For the first-time player with no prior knowledge of Mario or his exploits, very little is presented as far as story or objectives go. The game begins with a lone figure standing in front of a green hill on a blue sky background, with a single white cloud high above. The words "Super Mario Bros." on the title screen suggest that this is Mario, or at least one of the "Mario Brothers," whoever they are. Walking to the left does nothing. Mario cannot interact with the hills or grass at all. But walking to the right reveals a bit more of this world. The screen smoothly scrolls as Mario walks to the right, and soon the first pieces of interactive architecture appear, as does another habitant of this world - a walking mushroom man, known as a "Goomba."
In thirty seconds of play, the player has discovered Super Mario Bros.' primary objective: move to the right. At an abstract level, this is all the player needs to know. If we were to write a computer program to play the game for us, it would need to know nothing of the backstory, the characters, or what's at stake if Mario fails. It would only need to know that its goal is to proceed to the right and recognize that if it cannot proceed to the right, it needs to attempt a different tactic for advancing.
There are of course some limitations and rules presented to the player along with his "move to the right" quest. The player must keep Mario alive to continue his eastward progress, so traps and enemies must be overcome. Each level (subsection of a single world) in the game has a 400 second time-limit, and Mario dies if he does not reach the end of the level within that time. The player begins with three lives, and loses a life each time Mario dies. If the player runs out of lives, his game is over, and he starts back over at the first level. Even with these restrictions, the game's objective can be described in such simple terms as "move to the right, don't die, don't let the time limit expire."
Compared to today's games always moving to the right is a downright basic objective. But its genius is in its simplicity. It is incredibly simple, easy to explain to a friend, easy to learn, and easy to remember. The end of each level is rarely more obscure than just "to the right", so players aren't left feeling lost or confused about where to go or what to do next.1 Since the player always knows in which direction he needs to move, he can put his brain power towards deciding on the exact path and tactics he wants to use to get there. The two-dimensional nature of the game excludes the possibility of a horizon line the player can use as a compass, so in effect the right edge of the screen is the horizon - the point at which the area immediately in front of the player becomes visible, as well as the point where the player's future becomes obscured.
As games have become more complicated we've started using more cues to help tell the player what to do, and you can rarely over-communicate the player's objectives or options. (Granted you can be overbearing or annoying about it, but if the player wants to know something, you need to have a mechanic in your game to get him the information he needs.) While a more modern game would almost certainly spell out the game's objective in text, dialog and iconography, I'd argue that since Super Mario Bros.' objective is so easily discovered and is so consistent, that extra explanation is not missed, and very few players are ever lost or confused about what they are trying to do next in the game.
Not surprisingly, reading the manual to Super Mario Bros. does not inform the player much more than playing the game for five minutes does. The player is told some more specifics - that each level ends with a castle and that jumping on the flagpole can score additional points. The story in the manual about Princess Toadstool and her "mushroom retainers" being held in the castles does help reinforce and explain the reasons for the game's overall objectives. Mario must run to the right because that's where the next castle is. Mario must not die because he needs to save the Princess. And finally, while the manual doesn't spell out why Mario must reach the castles before the time limit expires, it isn't a stretch to imagine that it is because King Koopa has a schedule to keep.
Give the Player the Control
Miyamoto's games are most often praised for their fine-tuned player controls. Super Mario Bros. set the standard for responsive controls in the 2D era. Other games of the era, even hit games like Castlevania and Mega Man, feel slow, clunky, and unresponsive when compared to Super Mario Bros. Highly responsive controls give the player a feeling of empowerment, and beyond that, enable her to be expressive in her mastery of the controls and the main character's abilities. Super Mario Bros.' simple, consistent controls are easy to explain and easy to learn, making the game accessible to a huge audience, and they are, in my opinion, one of the primary reasons for the game's massive popularity and commercial success.
Like most action games, Mario's movement and actions are directly controlled by the player through pressing buttons on the controller. Pressing left or right on the directional pad makes Mario walk left or right. Pressing the A button makes Mario jump, and pressing the B button makes Mario throw a fireball, if that power is enabled. Pressing down on the d-pad while in "Super Mario" mode makes Mario duck. While seemingly simple, there is complexity and depth to be discovered and mastered by the player. Simple combinations of interactions give Mario additional abilities. Holding down the B button while moving makes Mario run faster; holding down the A button makes Mario jump higher; running and then jumping lets Mario jump further; and using the d-pad while mid-air can influence (slightly control) Mario's movement before he hits the ground.
Once a player has mastered these combinations, there are some "emergent" abilities to master. A skilled player can wedge Super Mario under low overhangs that he normally cannot fit into by sprinting, ducking, and then sliding under the overhang. The first time a player sees this her reaction is likely to be "wait, wait… you can't do that!" It's unclear if this was an entirely intentional inclusion in the game, or if it's something that players uncovered after spending countless hours in the Mushroom Kingdom. Another similar ability is the duck-jump. While ducking the player can jump, and then air-steer a still-crouched Super Mario into small spaces that only "normal Mario" can fit. And almost certainly not intended by the game creators is the "wall climb", where the player can wedge Mario between the left edge of the screen and a column of bricks, essentially climbing her way out of the normal play area and up onto the "roof" of the level.
This is not to say that all games need hidden and emergent combinations of abilities, but they do need simple, clean controls. By assigning each device (d-pad, button) on the controller a clear function, the player is able to experiment by combining button presses and the sequences of button presses. The depth of controls has grown over the years, both in the Mario series and games at large. But the Mario games remain singular in that they present both challenges (button combinations) and rewards (animations, sound effects, abilities) to the player in the controls. Even before the player embarks into a level to take on the more concrete challenges, she is having fun being and puppeteering the main character. If you can make your game fun from the first second the player picks up the controller, you have a head start towards creating a game that's fun for the long haul.
Challenge the Player
Challenges are what we game designers throw at the player to keep him engaged in our games. Challenges are the "main course" of the gameplay: the largest percent of the player's time is spent overcoming challenges, or strategizing about how exactly he will attempt to overcome the next challenge. Even the game's objectives can be viewed as very large composite challenges. To "win a game" the player must overcome a series of smaller challenges. When we sit down to design a game and answer the question "what does the player actually do in this game?" the question we are actually attempting to answer is "what challenges will the player have to overcome, and in what order are we going to present these challenges to him?"
As such, challenges are a critical part of how fun and successful a game is. If a game is described as being too-easy, too-boring, or too-mundane, I believe it is being described as not challenging enough. If the player is not actively engaged, putting some effort into an endeavor, he has no chance of feeling good about himself once he's overcome the challenges. I don't mean to say that all games need to be "hard" or "difficult", but the game has to engage the player and ask (if not force) him to overcome challenges with his mind, his body, and his heart. A fascinating description of the allure of challenges can be found in Cziksentmihalyi's Flow.
There is definitely an art in designing the challenges for game, selecting the pace at which they are presented, and then combining them to create new, interesting experiences for the player. Super Mario Bros. is a fantastic study of the types of challenges in videogames, and most of these patterns can be found time and time again in modern games. All action/adventure games, from Crash Bandicoot to Half-Life have these patterns with only slight alterations, adjustments and improvements.
The overall goal in Super Mario Bros. is to complete the last level and rescue Princess Toadstool. To achieve this, the player must first complete a series of levels leading up to the last level. And to do this the player must reach the end of each level without dying before the time limit expires. To reiterate the simplified goals of the game again: run to the right, don't die, and don't let the clock expire. These are the persistent challenges that the player must face at all times during gameplay, independent of what level the player is currently playing, how long he's been playing, or how many lives he has. Meanwhile, each level in the game is a collection of new challenges that only exist in that level. The level is a "bundle" of challenges if you will, and once the player has completed a level, he doesn't have to worry about the challenges of the prior level, only the challenges of the level ahead.
The level-specific challenges in action games can be split into "environmental challenges" and "enemy challenges". Environmental challenges are challenges that are built into the virtual game world - they are the inanimate objects, obstacles, and traps that the player must overcome as he traverses the game world. Meanwhile the enemy challenges are the free-roaming characters that oppose the player in his pursuit of his objectives in the game. As such, the player must defeat, outsmart or avoid these enemies when he comes into contact with them. The levels in most successful action/adventure games have a mix of environmental challenges and enemy challenges, often half and half, as each presents its own particular flavor of gameplay, level of risk, and types of rewards.
The design of each level in Super Mario Bros., from start to finish, can be thought of as a single large composite environmental challenge with multiple enemy challenges placed within. It is the composition of these numerous individual challenges that give a level not only a unique aesthetic, but also unique pacing, difficulty, and risk-level. Successive levels build on the challenges and skills required to complete the prior levels. When the player completes a single level he has proven to the game that he has mastered those skills and is ready for the next set of challenges. As such the player is rarely presented with a challenge he is not equipped to handle.
Environmental Challenges
A single brick sitting at ground level in Super Mario Bros. is enough to constitute an environmental challenge - the brick blocks the player's normal progress to the right. The player overcomes this roadblock challenge by using one of her abilities - pressing the A button while she holds the d-pad to the right, to jump over the brick and proceed through the level. Two bricks stacked on top of each other present a slightly more complicated challenge, as the player has to hold down the A button for longer to jump higher. A bottomless pit in the ground presents a different type of environmental challenge, this time one with some risk attached to it. The player uses the same ability as she did when jumping over a brick in her way, but if the player attempts to jump over this pit and fails, she falls into the pit and loses a life. So this challenge is one the player approaches with a bit more apprehension and care.
The third type of environmental challenge in Super Mario Bros. is the moving platform. While roadblocks and bottomless pits are challenges that can be accepted and attempted entirely at the player's leisure, a platform that moves in the world of its own volition, be it left and right or up and down, requires that the player use her jumping abilities as well as good timing. The jump itself might be simple, but timing it just right to safely land Mario on the platform, and not have him fall into the bottomless pit, requires more skill than a jump over a completely stationary bottomless pit. And since the moving platform requires more skill to overcome, there is additional risk of failure.
Super Mario Bros. features a fourth type of environmental challenge: traps. Traps often resemble tethered enemies (see below), but while tethered enemies can be dispatched by the player, removing them (and the threat they present) from the game world, traps are almost always permanent. Super Mario Bros. contains a number of such traps: the suction pits in the underwater levels, the spinning rods of fire in the castle levels, and the "Podoboo" fireballs that levitate from and then fall back into lava pits. Traps usually present a timing or dexterity challenge to the player that she must avoid to proceed, and are an effective way to increase the overall challenge level in a small area.
The sequence of levels in Super Mario Bros. is built by slowly increasing the skill required to overcome the environmental challenges - making the roadblocks taller, the bottomless pits wider, the moving platforms more narrow, and the traps more dense. Increasing the number and frequency of these challenges increases the amount of skill needed to overcome them. Jumping over a tall roadblock may be easy for the skilled player, but jumping over the tall roadblock surrounded by bottomless pits may give her pause.
Even though the player has seen and overcome all of the environmental challenges in the game by the time she completes the fourth level, Nintendo was able to sequence and recombine these challenges in numerous ways to create thirty-two unique levels with a fairly steady difficulty ramp. Each world presents a new mix and sequence of challenges, and even the levels that bare striking resemblance to prior levels in terms of structure have new traps or enemies in them to challenge the player that bit more.
Enemy Challenges & Combat
Enemies have become an essential part of action/adventure games, and as game designers we must not only design the challenges that the enemies present, but also how the player will overcome these challenges in the form of a combat system. While the player uses his movement and navigation abilities to overcome the environmental challenges, the player is often also equipped with combat abilities to overcome his foes. A modern game might equip the player with a button for jumping and another button for swinging his sword, delegating these abilities to separate modes of play.
Designing a combat system is a complicated affair, as you must not only consider the abilities and vulnerabilities of the player's character, but also of the enemies you design, insuring that the two match up in an appropriate challenging-but-fun manner. The character's abilities are what he will use to hurt his enemies, and the character's vulnerabilities are the ways in which his enemies can hurt him. This goes for both the player characters in a game and the computer-controlled enemy characters.
One of Super Mario Bros.' greatest innovations is that it ties Mario's movement abilities to his combat abilities, making the player use the same mechanic - jumping - to overcome enemies as well as navigate the traps and bottomless pits. Mario can jump on top of enemies to squish them, as well as "bump" a brick from below to knock-off the enemy standing on top of that brick. Mario's sole combat-focused ability of shooting fireballs is only available after eating a "Fire Flower", which is something of a rarity. Mario has one vulnerability: if he is touched by an enemy or trap he is hurt. If Mario has not eaten a "Magic Mushroom" to become "Super Mario" (affectionately known as "Big Mario"), then he dies when he is hurt. Mario dies instantaneously when he falls into a bottomless pit or pit of lava.
Mario's enemies collectively have a similar set of abilities and vulnerabilities. Most enemies injure Mario when they touch him on his side or head. Their touch is enough to reduce him to "Little Mario" or kill him. Some enemies can shoot projectiles, similar to Mario's fireball, and when those projectiles touch any part Mario, they hurt him as well. Every enemy in the game has at least one of the following vulnerabilities. If Mario lands on top of the enemy, the enemy is hurt. If, from below, Mario "bumps" the brick that the enemy is standing on, the enemy is hurt and often removed from the game. And finally, if Mario hits the enemy with a fireball, the enemy is hurt and removed from the game.
Some enemies in Super Mario Bros., like the iconic "Goomba" mushroom enemy, are vulnerable to all three types of attacks. These enemies present little challenge as the player can use any of his abilities to dispose of them. But other enemies are immune to one or two types of attack, and force the player to use and master a specific ability, perhaps one that he hasn't used lately. The "Spiny" enemies that appear halfway through the game are adorned with spikes along their top. As such the player cannot jump on them, and has to use a fireball or a bump from below to dispatch them. It's not that the Spiny is more difficult to dispatch than a Goomba, since the same bump ability is enough to defeat them. But the Spiny requires a specific tactic which might remove the player from his comfort zone and force him to explore an element of the gameplay that he hasn't before. In this manner the design of the enemies can provide much-needed variety and pacing control to the levels in which they are placed.
Enemy Movement Styles
The game designer must also consider the enemies' style of movement. No matter the enemy's abilities and vulnerabilities, if the enemy is completely stationary it won't pose much of a threat to the player. And in a game like Super Mario Bros. where the player is most often only hurt when the enemy comes and touches the hero, the enemy movement patterns are of vital importance to the game's design. While not featuring "smart" enemies or anything resembling what we've come to expect from artificial-intelligence in game characters, Super Mario Bros. does feature three archetypical types of enemies: tethered enemies, ambivalent enemies, and aggressive enemies.
Tethered enemies are enemies that are tied to a single location in the world, and are generally a low-risk enemy. Many of them resemble "traps" in the world, and these enemies lie in the grey area between environmental challenges and enemy challenges. Super Mario Bros. gives many of its traps and challenges personality - usually in the form of large cartoon eyes and a smile or frown. The Piranha Plant is the primary tethered enemy in Super Mario Bros. - its giant chomping green mouth resembling a Venus fly-trap rises from the pipes located in many levels, chomps a couple times, then lowers back into the pipe. Unlike a trap, the player can dispatch the Piranha Plant with a single fireball - but like a trap, jumping on it results in death.
Ambivalent enemies are characters that are free to move around the world, and generally don't respond to the player in the game world. Having a fantasy setting helps Super Mario Bros. in this regard, as the player has no preconceived notions about how a walking anthropomorphic mushroom should react to seeing a fireball-throwing plumber running at him. The most common and most recognized enemies in the game, the "Goomba" mushroom men and the "Koopa Troopa" turtles, are completely ambivalent to Mario's existence. For all intents and purposes, they are moving traps that the player must stomp or avoid. Roughly half of the types of enemies in the game, and certainly most of the individual enemies encountered in the levels, are ambivalent enemies. This illustrates Super Mario Bros.'s emphasis on platforming, and not on combat.
Aggressive enemies are the enemies that specifically go out of their way to attack the player. Often these are the characters that are not only in the same world as the player, but specifically on the bad guy's team. Super Mario Bros. features a handful of these enemies that present more of a challenge to avoid or dispatch, some of which can be downright annoying. The "Hammer Brothers" are a pair of such aggressive enemies. Often encountered in sets of two, the Hammer Brothers are turtles that have learned to walk upright and throw streams of deadly hammers at Mario. While technically vulnerable to being stomped, their hammers usually block this strategy, and so they can only be dispatched by bumping them or hitting them with a fireball. The fact that they often appear together in a signature structure of double-decker platforms makes them particularly challenging, and thusly a memorable event in the game.
Super Mario Bros.' cast of enemies have a creative mix of abilities, vulnerabilities and movement styles. Some enemies only walk on the ground, some fly through the air in a straight line, others fly through the air on large bounding arcs, and others still are bound to the water environments. But all of the enemies in the game are defeated or avoided by using Mario's simple, focused set of abilities. The player is never forced to learn a new mechanic or develop an entirely new skill to continue playing the game. Instead he is encouraged to master and hone his skills at controlling the abilities he does have. While this style of gameplay and game design might sound dated, the pattern reoccurs time and time again in hit games, from Half-Life to God of War.
Other Types of Challenges
While Super Mario Bros. is surprisingly thorough in terms of the challenges found in action/adventure games, it lacks a handful of challenges that have become increasingly popular as the lines between genres melt away. For example, Super Mario Bros. features almost no puzzles. The player has to use basic problem-solving skills to navigate through the levels, and the game features three "choose the right corridor" mazes, but almost never does the player have to stop running and jumping and start thinking hard about something. This could have been a conscious decision to keep the game accessible to younger gamers, or it could be a holdover from Nintendo's not too distant arcade roots.
Another style of challenge not found in Super Mario Bros. at all is creative challenges. Modern games often ask players to make choices that have no right or wrong answer, and are instead designed to let the player express himself and make the game more to his own liking. For example players can design their own character in World of Warcraft, or design their own cars in Forza Motorsport 2. But no such creative challenges exist in Super Mario Bros, and the series has been slow to integrate creative challenges, emotional challenges, and larger-scale player-created content.
Reward the Player
If challenges are what keep the player engaged in our game, then rewards are ultimately the reason she is playing at all. Rewards are what games give the player for overcoming the challenges, and to create a fun game the designer must balance the challenges the player faces with the rewards that she is given for doing so. If the challenges are the main course, then the rewards are the desert. It is my strong believe that the role of the game designer is to insure that the player is having a positive experience, and is enabled to have fun playing the game. Rewards are the single most useful tool in the game designer's toolbox, and are becoming better understood thanks to works like Flow.
One of the most rewarding things that a game can do is indicate that it is aware of the player and the player's actions. The primary difference between playing Super Mario Bros. and watching an episode of the Super Mario Bros. cartoon is the fact that the player is engaged and actively expressing her desires to the game via controller by working the d-pad and pressing buttons. The fact that Super Mario Bros. has such responsive controls directly makes the game more fun. The player is rewarded with a feeling of empowerment as she sees Mario perform her desired actions, accompanied by the appropriate sound effects and blinking sprites. This feeling of control and authority is terribly rewarding, and should not be taken for granted in favor of unresponsive controls or laborious character animations.
Reward Advancement
In a level-based game like Super Mario Bros. it's critical that you reward the player for advancing from one level to the next. It goes without saying that completing one level brings the player that much closer to completing her objective to win the game, and the player gets to look forward to seeing the next level, overcoming the challenges it presents, and collecting its rewards. But this is the absolute bare minimum, and Super Mario Bros. has several additional rewards attached to the completion of a level beyond that. The player is rewarded with a short animation of Mario running into a castle, a special fanfare tune is played, the player collects bonus points for having extra time left on the clock, and occasionally fireworks are shot from the castle, because hey, fireworks are just cool.
But the most interesting advancement reward in Super Mario Bros. is the Flagpole minigame. I use the term "minigame" here because in many ways it is a self-contained game inside Super Mario Bros. Most levels end with Mario ascending a series of stairs followed by a flagpole, and the player is rewarded a number of points based on how high on the pole she can land. Jumping to the top of the flagpole nets you maximum bonus points, jumping onto the base of the flagpole gives you minimum bonus points. The points themselves are rewarding, but the player can look forward to trying her hand at the flagpole again in the next level, eventually mastering the jump from the top of the stairs, and then graduating to trying to jump over the flagpole. It's a fascinating pattern that has rarely been copied, but I find it absolutely brilliant: reward the player for completing your level by letting her compete in a fun, low-risk minigame.
Reward with Visceral Audio and Video
Graphics and sound are another powerful reward in videogames, and at the time of its release, Super Mario Bros. was a technological marvel. Compared to the black negative space of Space Invaders, Pac-Man, and Donkey Kong, Super Mario Bros. is a visual masterpiece, featuring bright blue skies complete with happy little hills and happy little clouds. The visuals of the world change between levels, rewarding the player with something new to look forward to each time he completes a level. Above-ground levels, underground levels, underwater levels and castle levels each have their own visual style and background music. A fifth song was composed solely for the Starman power-up, making it a particularly special and memorable item in the game. And to further reinforce the game's super-tight controls, a sound effect is played every time the player jumps, every time he throws a fireball, and every time he dispatches an enemy. The player knows the game is listening to his input because he can see and hear it.
The enemies in Super Mario Bros. are rewarding in two significant ways. Firstly, seeing lively animated characters moving around in the expansive world is rewarding. It was particularly rewarding at the time of release as the characters were large, colorful, and recognizable. While "characters" on the Atari 2600 were often represented as barely recognizable blotches of color, the characters in Super Mario Bros. were fully formed and absolutely recognizable. Mario looks like a person. The Koopa Troopa looks like a turtle. And King Koopa looks like a big dinosaur dragon monster. But secondly, it is rewarding to dispatch your enemies. It's fun to squish a Goomba, and it's fun to kick a Koopa turtle shell across the level. Granted, it's the type of fun adolescent boys have squishing bugs on the playground, but it seems to me that this style of bug-squishing combat is preferable for younger gamers than encouraging the brain-splattering headshots of many modern games.
Reward Collection
Players love to collect things in games. They love to look for treasure, collect trinkets, and find hidden gems. I believe this phenomenon is built into human psychology: we love shiny things, and we love to fill our pockets with them. So any time you have the opportunity to have your player grab something shiny, do it. One of the most rewarding things that players can collect and accumulate in games is wealth. Even though the money in videogames is usually completely worthless and meaningless outside of the game, it is still an extremely powerful reward in the game. Players will assign the social status that comes with being wealthy in the real world to themselves as they play the game, and this can make for a more rewarding experience and a more fun game.
Super Mario Bros. has two collection mechanics, both of which are interesting given the time of the game's release. First the game has the player collect coins found floating in levels, hidden in visible and invisible bricks, stored in underground bunkers and in difficult to reach "cloud worlds." When the player collects 100 coins, he is rewarded an extra life. While the concept of limited lives has gone out of style now, back in 1985 an extra life was a big deal. Not only did it mean that you had one extra chance to complete that level, but if you look at it in arcade terms, it meant you might not have to put another quarter into the arcade machine to keep playing. So in many ways the virtual coins in Super Mario Bros. had the emotional value of real-life money to players of the day. The collected coins also give the player additional points, adding to his total score.
Again like most arcade games of the day, Super Mario Bros. kept track of points for the player. Points are a completely abstract construct, and are simply a tally of the player's actions in that game session. Nearly every action in the game, from defeating an enemy to smashing a brick, gives the player additional points. As discussed, the player is rewarded additional points for completing levels and for having time left on the clock. While the game features no high score board, the points did allow for playground bragging rights, and if you had a camera handy, you could take a snapshot of your high score before your mom accidentally unplugged the NES as she was vacuuming. Today high score boards have made something of a comeback with the likes of online gaming and leader boards, largely because they are a valuable way to give the player social rewards.
Reward with Items and Abilities
I would be amiss to not discuss power-ups. While points went out of style for a time, action games of the last two decades have consistently featured power-ups; letting the player to find and use new "stuff." We can broadly discuss this stuff as power-ups, but it takes many forms: swords and armor in fantasy-based games, rocket launchers and cloaking devices in science-fiction shooters, or stolen cars and firearms in open-world crime dramas. No matter what form they take, these items temporarily give the player new abilities above and beyond what his character can naturally accomplish. Few Space Marines can shoot down a hovercraft when the game starts, but after collecting a rocket launcher, it's no problem.
While Super Mario Bros. didn't establish this convention, it certainly makes excellent use of power-up items. Part of the secret to the game's successful use of powerups is simply how few there are. There are only four powerups in the entire game - the player can instantly learn what they do, there are so few of them that the player can remember what they do, and finally the player can memorize where they are hidden in the levels and look forward to getting them. In fact, the power-ups in Super Mario Bros. are so popular and well known that they are practically characters in their own right.
Touching the "Magic Mushroom" powerup converts Mario into "Super Mario" (aka "Big Mario"), which grants him the new ability to smash bricks with his fist (often confused for his head), and lets him absorb one injury from an enemy without dying. Touching the "Fire Flower" grants Super Mario his only combat-focused ability - shooting fireballs. Touching the "Starman" grants Mario temporary invulnerability, and all enemies he touches while blinking are instantly defeated. And finally, touching the green "1up Mushroom" grants Mario an extra life - not exactly a new ability, but a valuable reward none the less.
What makes powerups so alluring in all types of games is not only that they grant the player character new abilities, but the fact that the player can lose them. Since the abilities are only granted on a temporary basis, the player who's collected a powerup has that much more to lose when he dies. This adds a new tactical layer to the gameplay, where the player who has gained no powerups has nothing to lose, and might act more daringly, while the player who has gained a powerup or two might proceed with more caution. Interestingly enough the reverse is often observed in Super Mario Bros.: since the player that's collected a powerup is at least somewhat protected from death, he is likely to act with great abandon, flinging Mario over pits and in-between traps, while the player stuck as "Small Mario" proceeds more carefully, trying to hang on long enough to find a mushroom.
Give the Player Clear Consistent Rules
While giving the player a variety of challenges and rewards is important, it's equally important that these challenges and rewards be governed by a set of clear, consistent rules. It's consistent rules that allow the player to weigh her options, make choices with a degree of certainty that they are in fact good choices for her current situation, and eventually build up to emergent gameplay. We often talk about the player's need to learn to play a new game, to learn a new control scheme, or to master a new mechanic. This learning is an uphill battle when the game's rules are a moving target.
When a game features consistent rules the player can use a micro-version of the scientific method to explore the game world, learn its operating rules, make hypotheses about how she can interact with that game world, test her theories of interaction, observe the results of her attempted interactions, and then use the knowledge gained to make informed decisions about how to proceed in the game. Most players are unaware that they are channeling Galileo as they play videogames, but without following a similar process most videogames would be unplayable. As an interactive medium, videogames require an inquisitive mind and exploratory approach. Players must be willing to ask themselves "what happens when I do this?" as they press new buttons.
Super Mario Bros. is an excellent example of clear rules in videogames. One location of particularly clear rules is in the physics and physical properties of the game world. In Super Mario Bros. there is positive space and there is negative space. Solid forms like bricks, metal blocks and pipes makes up the positive space. The rest of the world is made up of sky, the negative space that objects can pass through. Mario, also being a solid form, cannot move through solid objects, and he will bump into or rest on top of positive space forms. The levels are designed with this premise in mind - and the player's primary challenge is navigating Mario over, under and across solid forms.
Being a game almost entirely about jumping, gravity plays a critical role in the gameplay of Super Mario Bros. Gravity is a consistent rule that players deal with on a constant basis in their real-lives, and its application in Super Mario Bros. is admirably simple and consistent. What goes up most come down. After jumping, Mario will fall until he lands on something solid. When Mario or one of the enemies in the game walks off a ledge, they fall to the ground. Even most of the flying enemies in the game, be they turtles with wings or fish with wings, bound through the world, leaving the ground for a moment only to have gravity pull them back down.
Exceptions to Every Rule
Once a player has learned the operating rules of a game it is difficult to convince her of anything otherwise. She would have to in effect unlearn what she's already invested time and energy to learn. This can make learning the exceptions to the rules a frustrating process. As a game designer you must not only consider what the player has learned playing your game, but also what she's learned from her prior experiences playing games and, gasp, in real life. Every player comes to your game with a host of prior experiences, and convincing them of things otherwise is to tilt at windmills. Super Mario Bros. absolutely has exceptions to its rules, as do most games. But at least these exceptions are easy to discover and come to grips with.
One of the most important such exceptions is the player's ability to change positive space into negative space. Once upgraded from small Mario to Super Mario, the player can jump up and hit a brick from its underside to smash it. The square that used to be solid and blocking physical progress is now empty, and the player and enemies are free to move through this space. While surprising to a player familiar with Donkey Kong and Mario Bros., this feature was not wholly unexpected in platformers of the day. Both Dig Dug (1982) and Lode Runner (1983) featured core gameplay based on turning positive space into negative space. The fact that the player is introduced to Super Mario and the new ability to smash bricks in the first minute of play certainly helps establish this exception to the positive/negative space rule as the player is forming her initial impressions of the game's ruleset.
An exception to the game's rules of gravity is the existence of the water levels. In these submerged levels water has filled the entire screen, and the player must swim through the water, avoiding new sea-life enemies as she races to the pipe that will lead her to the flagpole at the end of the level. Here the player has to learn to swim, the rules of which are similar to the rules of running and jumping, but differ slightly. The jump button is still used to propel Mario upwards, but instead of quickly falling to the ground, Mario slowly sinks to the seafloor while underwater. This allows the player to rapidly tap the jump button to propel Mario closer to the surface. All of the player's experiences in the prior levels are used to make the underwater mechanics digestible, and any experience the player has with swimming in the real world help make this exception to the rules easier to learn.
A final exception is one I remember being personally confused by the first time I encountered it in the game. The game does a good job of establishing that touching enemies is bad, as is falling into bottomless pits. Once the player has mastered these two concepts she is well on his way to completing the first level of the game. But before reaching the end of the level the player is presented with a Starman powerup, which at the time was described to me as "making you invincible." Already being intimately familiar with Superman I knew what that word meant, and so my interpretation was "oh cool, I can't die!" I grabbed the Starman and immediately ran off a ledge, expecting that Mario would not die from the bottomless pit below. How wrong I was. And so I learned that the Starman only protects Mario from enemies - not from bottomless pits or lava. While a little bit frustrating at the time, learning the exception would be even more frustrating if I hadn't already learned that becoming the big Super Mario protected me from enemies, but not from bottomless pits. Falling into a bottomless pit absolutely always resulted in death, but the power ups in the game were allowed to provide protection from enemies.
Let the Player Make Choices
One of the defining characteristics of videogames, if not the defining characteristic of videogames, is that the player is empowered to make choices. Players have infinitely more to say about the order, pacing, and often-times the inclusion of events in games than they do in literature, film, or television. As game designers we must empower and encourage the player to make choices, and then listen to his decisions and proceed accordingly. When we present challenges to the player it is up to him to decide how to overcome them, or to attempt overcome them at all. When we reward the player with new content and abilities, he can decide how to use these newfound abilities, or to ignore them in favor of a prior ability. And on a grander scale, it is up to the player to decide when to play the game, for how long, and to continue on the quests we give him… or not.
Super Mario Bros. is not the world's most choice-laden game. Many of the biggest decisions to be made are dictated by the game at the most fundamental levels. Where does the player want to go in the game world? Well, there is only one direction in which he is allowed to proceed: to the right. Does the player want to proceed at break neck speed or at a leisurely pace to take in the sights? Well, Mario can only run so fast, and if the player moves too slowly the time limit will expire. Does the player want to overcome his enemies with violence, or would he rather extend the olive branch and enter into peaceful negotiations? Well, there's no "olive branch button" in the game… so good luck with that.
But Super Mario Bros. does give the player a number of important choices to make throughout the game. While the player cannot select a new direction in which to run besides to the right, the player does get to select how he proceeds to the right. Most of the levels are designed to give the player the choice of taking the more solid low-road, or the more jump-laden high-road. The player is also presented with a number of choices about navigation on a higher level. Ducking down into a pipe can advance the player past a large portion of a level, but it also means skipping several rewards. Finding one of the game's "Warp Zone" rooms lets the player skip past entire levels and worlds, but that forfeits any points that could be collected by completing those levels. Despite the heavy-handed "always run to the right" rule of the game, the player is empowered to choose the specific path he takes though Super Mario Bros.
Despite the lack of an "olive branch button," it is up to the player to decide to engage the enemies in combat or not. There is no requirement or even explicit challenge to defeat all of the enemies in the game, and when confronted with one or multiple enemies, the player has the option to avoid them or to continue without harming them. The game does not explicitly reward this behavior, while it rewards the player for defeating enemies with points - so there is a pro-combat bias to the design. However, it is theoretically possible to complete the game and rescue the Princess without harming any enemies at all… up until the final showdown with King Koopa, who you must dispatch to meet the Princess.
Giving the player choices, of how to overcome challenges and how to use rewards, creates a more empowering, personalized game experience. When the player is not only solving problems but also feeling like he came up with how to solve them, the rewards he is given taste that much sweeter. Despite being a "linear" game by today's standards, Super Mario Bros. consistently gives the player small, but important choices to make that create the illusion that he is not only controlling Mario, but that he is in fact Mario, acting and thinking as Mario needs to act and think in these perilous situations.
Variety, Variety, Variety
A difficult lesson for designers to learn is that sometimes something different is better than something better. For a moment, imagine yourself at an ice cream shop with a "free ice cream every day for a year" coupon. What would your first week's worth of scoops be? Imagine that you dedicated yourself to the realm of chocolate: chocolate, chocolate-chocolate-chip, dark chocolate, chocolate with hot fudge… and so on. No matter how much you love chocolate, you'll eventually tire of this monotonous (yet delicious) diet, and venture out into the realm of vanilla, strawberry, butterscotch, pistachio, and mint-chocolate-chip. Just because chocolate-chocolate-chip ice cream is "better" than pistachio ice cream doesn't mean you want to eat it every day for a year.
We (humanity) have an insatiable appetite for what's new, or more specifically, for what we perceive as being new at the time. This helps explain the phenomenon of cyclical fashion, popular music, and why the same sitcoms keep getting made and remade over and over again with new names and younger actors. Often what's new isn't new at all, but it's new for the moment, and that's all that matters. Variety is the spice of life, and I'm afraid this cliché holds true in videogames. Failing to give the player something new at regular intervals will create a predictable, monotonous experience that the player tires of quickly. If you cannot meet the player's appetite for the new, he will stop playing your game once he's had his full and start playing someone else's.
Super Mario Bros. is not the spitting image of variety by today's standards. Mario cannot hijack a car, mount a giant flying owl, or launch a jeep out of an exploding space station. Mario can run, jump and swim. But for its time Super Mario Bros. set a high bar for variety with its many levels, enemies, powerups and surprises. When you discuss variety it is not only what you are presenting to player that's important, but also the order in which you present it to him. With careful sequencing you can create a game with a limited amount of total content but a great deal of perceived variety.
Let's examine a worst-case scenario of variety by redesigning the first four levels of Super Mario Bros. We'll begin by putting all of the roadblocks and nothing else into a single level. Then we'll follow that up with a level made up entirely of bottomless pits with little patches of ground between them. This will be followed by a completely flat level populated by all of the enemies. And the fourth level will contain nothing but coins, question mark blocks, and power-ups. The end result would be four of the most monotonous levels ever created.
The first level would contain no risk, and the player would simply bang on the A button to continuously jump over the roadblocks. The second level would be quite risky and stressful, requiring the player have excellent timing and jump-skills, but would contain no active threats. The third level would be completely overwhelming, as the player would have enemies coming at him from all directions with all manner of movement styles, abilities and vulnerabilities - the player would be lucky to make it through without a panic attack. And the fourth level would be a welcome respite, but it certainly would not make for a stimulating level due to its lack of challenges and risk.
Super Mario Bros. could have easily been that bad. These four levels contain the same elements that make up the entire game, and yet they are clearly bad ideas. My goal in doing this exercise is to illustrate the importance of careful composition of gameplay elements, and how the context of a gameplay element is almost more important than the element itself. In Super Mario Bros. the player is rarely given the opportunity to tire of a single element of the game. After facing a couple enemies the player has to overcome a roadblock. After a roadblock or two he is presented with a bottomless pit. And after clearing the bottomless pit he is rewarded with coins or a powerup. The levels in Super Mario Bros. are all slight variations on this pattern, escalating in difficulty, but rarely introducing completely new elements after the first world. And yet the careful composition of these elements through and across the levels creates a game that is rarely boring or monotonous.
While Mario's primary ability, jumping, is at the crux of nearly every gameplay mechanic in the game, the ways in which the player is forced to jump vary greatly. As the player progresses through the levels the mandatory jumps over roadblocks get taller, the bottomless pits get wider, weaker enemies are replaced with tougher ones, and the powerups become fewer and farther between. And just as the player begins to tire of running and jumping, he's presented with an underwater level. While the underwater levels in Super Mario Bros. are some of the most hated (in my household anyhow), they provide a needed and welcome change of pace to the game. Instead of running and jumping the player is now swimming and submerging, using much more of the screen as active game-space than before. And even for the player that absolutely hates the underwater levels with all of his being, they provide an important opportunity for the player to look forward to what's next.
To return to our ice cream shop analogy, imagine that you are on day thirty and have had one scoop of nearly every flavor of ice cream the shop carries. What are you thinking about? Are you thinking about the next day's scoop, which is likely to be the one you were least looking forward to… or are you thinking about returning to the top of your list, able to make an informed decision about which flavor is your favorite, and promote it to the top of the batting order? I know I personally would be looking ahead, and this is the sensation of anticipation that I experience when I play the underwater levels in Super Mario Bros. "Yeah this is ok… but I sure can't wait until I'm back on solid ground where I can run and jump again!"
Super Mario Bros.' mastery of variety and alternating experiences has been expanded and improved on over the lifetime of the series, not to mention often imitated. This imitation has been so great that it is now a cliché in videogame design to discuss a "desert world, water world, ice world, lava world, forest world" and so on. It became a cliché because it worked, both on the macro-level of worlds with different themes, but also on the micro-level where the player is never forced to do the same thing over and over and over again within a single level. A handful of simple gameplay elements can be arranged in nearly infinite sequences and combinations to create a huge variety of gameplay experiences, just as twenty-six letters can be arranged and combined to create a nearly infinite number of words and meanings.
Surprise the Player
You must surprise the player of your game. The reason "spoilers" in works of fiction are such a guarded and oft-argued subject is the simple fact that being surprised is "half the fun." A surprise is a specific type of emotional reward where the player (or audience member) is caught off guard, and forced to react to something that she didn't see coming a mile away. But technically speaking, you can surprise the player with any type of content. The surprise can be a challenge, where the player is forced to think on her toes about how to overcome it. The surprise can be a reward, where the player is delighted to receive an unexpected gift. Or the surprise can be an exception to a well-known rule, which has the effect of expanding the player's perception of the gameworld's complexity and possibility space.
There's an important difference between variety and surprises in games, and as a game designer, striving for variety is not the same thing as striving for surprises. Variety simply means that you present the player with something different than what she's currently experiencing and experienced before. Surprising the player means you present the player with something unexpected or something in an unexpected context.
Super Mario Bros. is so full of pleasant surprises that there are practically too many to count. The first-time player's experience is full of memorable discoveries about the game, its universe, and its rules. Putting yourself in the shoes of a first-time player a quarter century ago you can imagine the delight in the first five minutes of play. The first time the player walks to the right: "Wow there's more stuff over here!" The first time the player picks up a mushroom to become big: "Wow I'm huge!" The first time the player breaks a brick: "Wow I can smash stuff!" The first time the player finds coins in a non-question-mark block: "Wow there's stuff in there too!" The first time the player picks up a fire-flower: "Wow I can shoot fire!" The first time the player goes down a pipe: "Wow there's more stuff down here!" The first time the player hits an invisible brick: "Wow there's secret stuff!" The first time the player finds a beanstalk: "Wow I can climb up out of the world!" The first time the player finds a warp-zone: "Wow I can skip levels!"
Many of these first-time experiences weren't only new because the player had never played Super Mario Bros., but also because she'd never experienced these mechanics in any videogame before. This is not to say that these elements never existed in any prior videogames, but Super Mario Bros.' immense popularity meant it was being played by people with little to no prior experiences with videogames. Even players familiar with the likes of Pong, Space Invaders, Pac-Man and Donkey Kong could be surprised with the novelty of Super Mario Bros.'s large scrolling world. The very nature of a side-scroller means that the player can only perceive one screen's worth of the world at once. As the player progresses to the right, more of the world reveals itself, presenting new surprises one column of pixels at a time.
Assuming the player does not have a perfect memory, every time she plays a level in Super Mario Bros. she can be surprised by its contents. The alternating terrain of pits and roadblocks, the revelation of enemies, and the placement of bricks and question mark blocks make each level a new set of surprises ready to be experienced. Even after dying in a level and having to replay it a few times in a single sitting, the player can still be surprised when she learns the location of a 1up mushroom, discovers a new hidden block, or enters a pipe she hadn't before on her first, second, or third time through. The number of surprises and hidden content in Super Mario Bros. makes replaying the levels fun.
Later in the game surprises come to visit the player from off-screen. These surprises largely come in the form of enemies - flying characterized bullets and disembodied fire breath. These enemies act as two-part surprises. First the player is surprised when they enter the screen of their own volition, even though the player is not making forward progress. But secondly the player is pleasantly surprised when she discovers the source of these threats. The Bullet Bills are being fired by mounted cannons (known as Bill Blasters), and the fire breath is coming from King Koopa (or one of his many doppelgangers). In this way the surprises turn the unexplained into the explained, and the operating rules of Super Mario Bros.' universe become more solid in the player's mind.
Conclusion
Super Mario Bros. is arguably the most influential videogame of all time. While it would be easy to blame this on its sales or on the marketing genius of Nintendo, I believe it is because the game is a milestone in the history of all game design. The game's universally understandable rules, instantly learnable controls, challenging but fun obstacles, absolutely infectious rewards, huge variety and numerous surprises made the game stand head and shoulders above other games of the era, and just as importantly, influence an entire generation of game designers. Without Super Mario Bros. it is difficult to imagine a world with Metroid, Castlevania, Mega Man, Sonic the Hedgehog, or Crash Bandicoot, not to mention the endless number of games in other genres influenced by its design.
Super Mario Bros. is a Rosetta Stone for all game design. Its simplicity and elegance makes it infinitely easier to "read" than modern games of comparable success, but the fundamentals that make Super Mario Bros. fun are the same ones that make the likes of Half-Life, World of Warcraft, and Guitar Hero fun. The lessons learned from Super Mario Bros. can be applied to any game of any genre of any platform of any era, and it has become crystal clear to me over the years that Miyamoto and Nintendo have done just that, learning from and building on the core of Super Mario Bros. and applying it to everything they create. One must look no further than Wii Sports. The only game to ever outsell Super Mario Bros. was created by the same company two and half decades later. This is surely no accident, and as game designers it would be folly to not sit up and look closely at the universal patterns these games share in common. Both games are instantly accessible, easy to control, challenging at an appropriate threshold, overflowing with rewards, and full of variety and surprises. The answers to our industry's greatest questions, like "how do we make our games fun?" can be found in Super Mario Bros. and Wii Sports alike.
1 The exception to the always-move-to-the-right objective is the three maze castles near the end of the game, where the player has to decipher the correct path to take through the castle to reach the exit. However by this point the player has mastered this objective, and this twist acts as a nice surprise to the advanced player.