Throughout the winter of 2006, I was a contractor with Large Animal Games in New York City, working on LEGO Bricktopia, a Breakout-style game targeted at the casual gaming market.
Since I’d never been a large consumer of Breakout games, my obvious first steps were to survey the contemporary market as well as research the genre to gain some historical perspective. The results of this exploration, along with “sage wisdom” from my on-the-job experience designing Breakout-style levels are the basis for this article.
Genre Overview, A Brief History
Breakout, Arkanoid, and just about every “paddle & ball vs. blocks” videogame you can name have roots that go back as early as 1967, when Ralph Baer designed the Magnavox Odyssey game system and the paddle controller. One of the seminal games for this system included a “paddle & ball” game mechanic, making it the great-granddaddy of the Breakout genre (many mistakenly assume the paddle & ball game mechanic originated with Nolan Bushnell’s Pong, Atari, 1972).
Years later, Nolan Bushnell and Steve Bristow, along with Steve Jobs and Steve Wozniak (of Apple fame) took paddle & ball game play a step further when they designed and developed Breakout (Atari, 1976). This was the first game to include the “paddle & ball vs. blocks” game mechanic integral to subsequent games in the Breakout genre.
In 1986 the Breakout-style game took a radical leap forward when Sega released Gigas and Gigas Mark II, games which introduced innovations such as: rich graphical backgrounds, power-ups, and falling objects which the player must avoid.
That same year Taito/Romstar muscled into Breakout territory with the release of Arkanoid. Although a later arrival than Gigas, Arkanoid is possibly the most popular game of the genre, and the one which most notably defines the “paddle & ball vs. blocks and other stuff” game play we know today.
Core Elements of Breakout-style Games
Every game genre has its originator(s), followed by an inevitable string of clones that introduce one or two new features. The Breakout genre is no different. While the original Breakout offered very limited level design and target object variety, a legacy of cloning and incremental improvement now presents us with a large number of features which are considered “core” to Breakout-style games.
Multi-hit breakable blocks – blocks form the bulk of most Breakout-style game levels. In some games variation in block durability (single or multi-hit) is used to create a more complex playfield.
Block and ball size variation – larger blocks and balls generally make for a shorter, easier game since it becomes easier to get the ball to a specific target. Conversely smaller blocks and balls increase the level of difficulty (due to reduced target size and visibility).
Block color variation – color can be purely cosmetic and used to create representational game levels (see Level Design – Common Structural Archetypes, later in the article). It can also have a specific meaning; with different colors used to designate different properties (number of hits required, higher point value, etc).
Unbreakable blocks – the primary purpose of unbreakable blocks is to limit access to level objectives (or repeatedly channel the ball). Unbreakable blocks sometimes have special properties like rebounding the ball at a faster speed, or disintegrating once the ball hits a special switch or trigger.
Power-ups – there are so many types of power-ups that I won’t even attempt to describe them all here. However, I will list the archetypes that seem to appear in most games: (a) ball adheres to paddle, (b) ball is slowed, (c) ball damage increases, (d) ball becomes larger, (e) extra ball in play, and (f) paddle becomes wider. Some power-ups like “ball becomes larger” can actually be power-downs depending upon where the ball is when the power-up takes effect…
In most cases power-ups fall from block formations (when hit) and need to be caught on the paddle to take effect. This provides the player with a significant choice between chasing down the ball or going for a much-needed power-up.
Power-downs – as above, I’ll simply list the most common archetypes: (a) slow paddle, (b) narrower paddle, (c) fast ball, (d) tiny ball. When these fall from block formations, it is usually obvious to the player that they are negative, so he/she can take care to avoid them.
Ball trajectory controllers – there are several common trajectory controllers usually seen in Breakout-style games: (a) the mechanism, which grabs the ball and ejects it upon a trigger event, (b) the hole, which sucks the ball in and auto-releases it at a pre-determined trajectory, (c) the wedge shape, which forces the ball to return at a less predictable angle, (d) the channel (or arrow), which constrains the ball to move along a new vector (see Paper Ball: http://www.e-giraffa.com/). Trajectory controllers can prove extremely challenging depending upon the “return angle” of the trajectory controller and its distance from the paddle (or bottom of the screen).
Ball speed amplifiers – speed amplifiers usually take the form of persistent pinball style bumpers which rebound the ball with increased velocity. However they can also be playfield regions with a “speed amplifier” property that accelerates the ball as it passes through them (good for shaking up the player’s sense of timing).
Moving power-ups and power-downs – some games provide power-ups with limited motion (oscillating, path-based, or logic-based) which makes them harder to obtain, increasing the challenge. Moving power-downs (with homing capabilities) are also a great way to turn the tables on the player.
Switches (ball locks, trigger areas, buttons) – switches are often used to open up “reward areas” of a level by destroying large numbers of normal blocks or unbreakable blocks. Switches can also be used to activate boss enemies, set additional targets into motion, etc. Ball locks can be triggers, or trajectory controllers (see above), catching the ball then shooting it at another switch or a bomb (see below).
Ball traps – ball traps are small gaps in block formations that hold a payload of one or more balls. When the player destroys enough blocks to breach the ball trap, its payload of balls is released. Ball traps also take the form of objects which must be hit or broken in order to release their payload (wooden crates, glass containers, etc).
Bombs – bombs can be free-moving, but are usually stationary, nestled within a formation of blocks. When hit with the ball they explode, carving out small chunks of blocks or setting off major chain reactions.
Shields – shield are a special class of power-up that blocks the ball from falling off the bottom of the screen. Shields can last for a specific duration, or for one ball-hit per shield layer.
Invisible blocks – these blocks start in an invisible state and only become visible for a short time after one of them is hit.
Progressive blocks – each time the ball hits the paddle, the wall of blocks descends a small amount towards the bottom of the screen. Players must focus on breaking the lower wall of blocks (or simply trying to score as much as possible) before they are overwhelmed.
Multiple paddles – this feature presents the player with two paddles, one above the other. Additional options include adjustable spacing between the paddles, independently varying paddle sizes, and changing the points awarded for using a particular paddle.
Innovations of Contemporary Breakout-style Games
Any attempt to google “breakout game” will certainly be rewarded with a massive number of links to downloadable demos. This proliferation of Breakout clones is probably due to the speed with which a novice programmer can cobble together a Breakout prototype. I’d like to say most of these games are fun to play, but the truth is the novelty has long worn off classic Breakout-style game mechanics, thus innovation and differentiation have become critical in pulling off a contemporary Breakout-style game.
Below I highlight some of the more recent features to appear in the genre, along with a game or two you can download to see the feature in action:
Extensive motion on majority of game objects – today’s Breakout-style games are often very dynamic, presenting the player with a large amount of animation. From blocks that simply oscillate back and forth or move between pre-described coordinates, to “smart” objects that interactively respond to the game play environment and player. See Ricochet:Lost Worlds for a good example of motion (http://www.ricochetlostworlds.com/).
High-fidelity physics/motion simulation – the higher speed of contemporary CPUs allows developers to invest more processing cycles towards providing quality physics simulation for all objects, not just the ball. See BreakQuest and the DynaMo motion library (http://home.iae.nl/users/starcat/dynamo) for further information.
Particle effects – with the advent of graphics accelerators and powerful CPUs, particle effects have come into their own. Sparks, glows, and particle fountains bring previously static levels to life. In particular, “ball-trails” have made perceiving the ball’s motion much easier. LEGO Bricktopia uses ball trails and background texture perturbance to make the ball’s position as obvious as possible. (http://www.largeanimal.com/games/deluxe/lego-bricktopia). And then there is Plasma Pong (http://www.plasmapong.com/). While not actually a Breakout-style game (it’s Pong…) it does use particle effects, in the form of an impressive fluid dynamics simulation.
Moving beyond blocks – some games (notably BreakQuest: http://www.nurium.com/) get rid of blocks and replace them with extremely dynamic target objects. The result is a considerable increase in play variety. You will also find a large variety of target objects in Magic Ball 3 (http://www.alawar.com/games/magic-ball-3/).
Narrative and multi-level objectives – motivational prose for Breakout-style games has come a long way since “SMASH! POW! CRUNCH! A brick wall appears at the top of the screen…” Take a look at Funkiball Adventure (http://www.funkitron.com/games/funkiballadventure). Who would have thought that you’d one day be searching for stolen artwork on a Breakout level…?
Humor – games such as Jardinains 2 imbue Breakout-style play with much more humor and character than one would expect from a wall of impassive blocks (http://www.jardinains.com/). Be sure to play with the sound on.
Paddle bump – Funkiball Adventure was the first Breakout-style game to “break” the bounds of the bottom of the screen by allowing you to “bump” your paddle, raising it a small amount in order to strike the ball sooner and with increased force. Besides enabling super powered hits and splash damage to block formations, this simple control modification greatly increases your ability to manipulate the ball’s trajectory (http://www.funkitron.com/games/funkiballadventure).
Paddle construction – LEGO Bricktopia is the first game I’m aware of to let players significantly modify the structure of the paddle, in this case, by stacking it with LEGO blocks (http://www.largeanimal.com/games/deluxe/lego-bricktopia).
Advanced trajectory controllers – the game Paper Ball makes extensive use of trajectory controllers to direct the ball on circuitous courses through its levels (http://www.e-giraffa.com/).
3D graphics – while contemporary Breakout-style games with 3D graphics engines restrict the ball to 2D motion, most allow stacks of target objects to extend beyond that 2D plane. In some ways this simply creates a variation on multi-hit blocks, as eliminating the lowest row of blocks simply causes the stack to descend. Magic Ball 3 applies actual physics, which allows 3D objects to tumble and roll, disturbing other objects on the level and creating unpredictable chaos.
System Design, The Playfield
The Holy Trinity – Paddle, Ball and Blocks
Although it will seem remedial to mention this, all Breakout-style games have at least three things in common – each contains paddles, balls, and target objects for the balls to hit. When dreaming up a new Breakout-style game, there’s no right answer as to which you should design first. If your game is based around an incredible variety of targets, then coming up with your core targets will suggest the type of paddle and ball you’ll need. Conversely, if your game play revolves around a “super paddle” or novel type of ball, then the initial properties you dream up for these will suggest properties for the other playfield objects.
Blocks and Playfield Scale
When designing prototype levels, one of your first tasks will be to determine the scale of your blocks (or other target objects) versus the size of your playfield. Smaller blocks make it easier to design representational levels and complex play areas (see Level Archetypes below). Larger blocks make level design a faster process, but also necessitates you provide a wide variety of block types in order to keep the level from looking boring.
Once you have determined a scale for your playfield and blocks, you can work out the low/average density of blocks on a level. 50 blocks? 100 blocks? 200 blocks? 400 blocks? This will help you determine the required striking power of your ball/paddle (see Ball Speed and Damage below) as well as the types of blocks and power-ups that would be most appealing for your game.
The empty space surrounding your blocks (voids and playfield background) should also receive some thought. Voids highlight and contrast your target object structures, and also determine how interesting the ball’s motion will be. Cramming too many blocks onto the screen can overly restrict the ball’s motion and create a boring start to the level. If you plan to crowd a level, think about using power-ups, switches and bombs to quickly create (and reshape) voids.
While a simple black background provided good contrast for classic Breakout level structures, contemporary games contain animated backgrounds, or backgrounds that interact with the ball as it passes through (for example: having the ball illuminate the background image/texture).
Is your game “slow and sneaky” or “fast and furious?” The base speed of your ball and the base horizontal movement and striking speed of your paddle will have an impact on the perceived character of your game. Thinking about them upfront can help you avoid having to change audio/graphics to suit a game whose character has changed due to major speed adjustments. While there is no need to lock your game to a single play speed, you should always rely on play testing to determine the best speed(s) for your target audience.
One of the most important initial decisions you can make is how your paddle handles and how its surface rebounds the ball, as this will determine the amount of control your paddle offers the player. Throughout the development process ask yourself “When missing the ball, does the player’s frustration center on their lack of skill, or do they blame the paddle?”
Paddle Speed and Size
Here are two important rules to remember. (1) The greater the paddle’s horizontal movement speed, the easier it becomes for the player to reach the ball. (2) The wider the paddle striking surface, the easier it becomes for the player to hit the ball upon reaching it.
Let’s take a closer look at two paddle archetypes: Slow/wide paddle vs. Fast/narrow paddle. Although functionally able to deliver similar amounts of coverage, they do not deliver the same type of play experience.
Slow/Wide paddle – The slow/wide paddle will provide a more casual game play experience, with the player needing to anticipate the ball’s return trajectory but not worrying a great deal about the point of contact (where the ball hits the paddle), due to the wide paddle surface.
Fast/Narrow paddle – a fast/narrow paddle still requires the player to anticipate the ball’s return trajectory somewhat, but the small size of the point of contact instills a continuous sense of jeopardy. This creates substantially increased tension as the player attempts to intercept the ball for a return volley.
Thus a “purist” game with static levels and very few power-ups might want to have a slightly narrow, slightly slower paddle. While a game with many moving objects and power-ups on its levels might want to provide the player with a slightly faster and larger paddle since there are probably many other things competing for the player’s attention.
Moving blocks make it very hard to judge the ball’s return trajectory, so if your game uses a lot of moving blocks, you should probably increase the initial size of the paddle. Of course, as your game progresses, you can always introduce effects that shift this balance around…
Paddle bump is an interesting addition to the list of paddle abilities (seen in Funkiball Adventure, LEGO Bricktopia). It allows the paddle to move upwards slightly in order to address the ball sooner. This allows the player to create a much wider range of shot angles and often allows the player to power-up the ball, increasing its striking damage and speed.
When introducing paddle bump you need to take into account five things: (1) How far upwards the bump takes the paddle. (2) How fast the paddle can bump upwards. (3) How fast the paddle returns to its normal level. (4) Whether or not the bumping paddle powers up the ball with increased speed, splash damage, etc. (5) Whether or not repeated paddle bumps continue to power up the ball to higher levels of velocity and damage.
Paddle bump has several benefits. Most importantly, it allows players to have a greater degree of control over the ball (as shown in the diagram below). The amount of control over the return angle does not appear to be much in the context of a single strike. However, when multiplied over hundreds of strikes per level it turns out to provide a considerable advantage over a completely 1-dimensional paddle. If paddle bump also increases ball speed, it can provide a further boost to control which is very useful on non-static game levels. (Note: if a powered-up ball hits an “unbumped” paddle, try demoting the ball one step towards its normal state.)
Paddle bump also gives the player something to do while they are waiting for the ball to return. This may seem strange, but idly bumping the paddle can be a lot of fun! Especially if there is an associated visual effect and sound. Think of it as tapping your foot to a catchy tune.
Finally, paddle bump makes the game feel more dimensional. Instead of locking the player to the exact bottom of the screen, the player is given a little wiggle room to advance into the playfield. (Note: for an example of a game that does not use paddle bump, but still allows the paddle to advance into the playfield, see Nervous Brickdown for Nintendo DS, from Arkedo.)
The earliest Breakout games used rectangular paddles with flat surfaces. The ball’s trajectory would be influenced by the part of the paddle the ball touched, with the edges providing a flatter bounce trajectory.
Today’s Breakout-style games provide a much wider variety of paddle shapes including hemispherical and isosceles trapezoid (flat top and bottom with wedge-shaped sides). Unlike completely flat paddles surfaces, these paddles help to suggest how they can control the ball. The combination of isosceles trapezoid with paddle bump provides a remarkable level of ball control (LEGO Bricktopia).
Besides speed, size, shape and bump, you also need to think about the transmissive properties of the paddle surface. In particular, friction – how much of the paddle’s horizontal speed is translated to the ball upon impact. Paddle friction is one of those things you can live with or without. I tend to favor paddle friction because it gives the player more control over the ball and makes the paddle feel a little more tangible. You can break paddle friction down into three basic categories:
The reflective paddle – this equals ZERO friction. The paddle imparts no spin and reflects 100% of the ball’s energy back to it like a stationary glass wall. Of course, in real life there is always some energy transferred from the ball to any surface it touches, but breakout “breaks” those rules to keep the ball moving fast. In practice this paddle simulation requires the least CPU cycles, but provides the least dynamic play since every interaction with the ball is fairly predictable.
The paddle with simple friction – this paddle’s surface transfers a portion of its horizontal movement to the ball, thereby changing the ball’s trajectory. For instance, if the paddle is traveling in the same direction as the ball, it will leave at a sharper angle whereas if the paddle is traveling counter to the ball’s horizontal movement, the ball will reflect off the paddle more directly upward.
The paddle with friction and ball spin – the next step up from a paddle with simple friction is one that can also impart spin to the ball. Here the paddle surface translates a portion of its horizontal movement to the ball as both linear and angular velocity. A spinning ball will bounce off other surfaces at a sharper or shallower angle much as a spinning pool ball will reflect off a bank differently based on its spin.
Further Paddle Enhancements (Super Paddles)
While most paddles only alter the ball’s trajectory, maintaining a fairly constant speed, there are also games with paddles that add significant additional energy (via paddle bump for example). These “super paddles” don’t necessarily have friction or impart ball spin. For two good examples of super paddles see Funkiball Adventure or LEGO Bricktopia.
Pardon me for pontificating, but one day I hope to see a Breakout-style game that allows the player to instantly cycle through a range of available paddles with a right-click of the mouse. I mean, in an FPS you have a multitude of guns right? Similarly, I think it’d be great to have a ball with user-selectable properties, allowing the player to cloak the ball, or switch on self-illumination on a dark level, or perhaps even make the ball intangible for short periods of time (all with a right-click of the mouse). This would open up a multitude of possibilities in level design!
Ball Speed and Damage
For classic Breakout games, the extent of ball speed and damage is simply this – the ball moves at a fixed speed and breaks one block with each strike. This rule continues unchanged, with the ball moving at the same speed, doing the same amount of damage, level after level… Some games change the ball’s speed and damage potential through the use of Power-ups, or increase the default speed as the player progresses to higher game levels. Funkiball Adventure was the first genre game to significantly break this mold by introducing paddle bump; enabling consecutive ball hits to increase the ball’s speed and striking power.
At high speed and power levels, the ball imparts splash damage, fracturing or completely destroying adjacent blocks. There are a few reasons to consider this an improvement over simple power-ups. First, it puts control of ball speed and power firmly in the player’s hands, at all times – as opposed to giving this control over to the random distribution and collection of power-ups. Second, it allows players to self-regulate game speed and dynamism – players with less skill, who frequently miss the ball, or who don’t paddle bump, get a decline in speed and power.
The Ball Motion Simulation
A critical component of any Breakout-style game is a compelling simulation of ball motion. In general, the ball starts with fairly predictable movement, generating fantastic motion under the effect of power-ups (or paddle bump). Let’s take a closer look at the motion simulation, starting with its common state, with no power-ups or other extreme properties acting upon it.
The bouncing ball – this is your no-frills Pong-style ball. It bounces around, perhaps gaining or losing energy from objects it strikes. It has a perfect center of gravity and doesn’t spin.
The bouncing and spinning ball – in games that utilize surface friction, ball spin becomes possible. The simplest implementation uses a perfect sphere with a stable and “perfectly centered” center of gravity. Spin is used to modify to the ball’s trajectory coming off the paddle (or any other game surface) but doesn’t create any truly complex ball motion.
The complex ball – a more complex ball (non-spherical, semi-solid or aggregate object) will have a “complex” center of gravity and perhaps variable friction depending upon which ball surface contacts the paddle. Some examples of complex balls include: an egg-shaped ball, a square rubber sponge with a rock embedded in one corner, two basketballs connected by a chain.
A Look Under The Hood
A classic Breakout-style ball simulation can be created rather easily. However, once you include spin, complex balls, or move to a full physics simulation, complexity quickly spirals upwards. I asked Josh Welber, lead programmer of Large Animal Games’ LEGO Bricktopia, for some tips on managing the ball simulation.
Is there an obvious point where ball motion becomes too complex to manage with a simple motion simulation?
Josh Welber: A simple motion simulation where the ball reflects perfectly from collision works well if you are going for the classic Breakout mechanic where: (a) all obstacles are rectangles, (b) the walls are always static and, (c) the ball has a constant velocity.
When you start adding arbitrarily shaped obstacles and walls, animated obstacles, or want a more realistic and variable ball motion, you will want to consider a more general physics solution (either home-grown, or built out of one of the many open source packages: http://en.wikipedia.org/wiki/Physics_engine).
Is there anything developers should look out for when using a full-blown physics system in their Breakout games?
JW: The tricky part of working with a more generalized physics simulation is that Sim tends to want to control everything.
For instance, artificially changing the velocity of the ball or other properties of the world can upset the simulation. Most robust systems will allow this to happen at some point in the integration/collision loop.
However some systems rely, for instance, on the velocity vector to determine how to resolve collisions over multiple steps – artificially changing that vector inbetween integration loops can “fake out” the physics simulation, causing it to resolve collisions incorrectly.
What impact did this have on developing LEGO Bricktopia’s implementation of fast