[Veteran mobile and casual game developer Tony Ventrice, currently at social game firm Playdom, examines the difference between hardcore and casual play mechanics -- and dispels commonly-held myths about which are which.]

What qualifies a game as casual or hardcore? It's a question essential to anyone designing for a broader audience and, with games on Facebook and other social networks making headlines, one might expect social game developers to be leading industry discourse on the topic.

Yet, surprisingly, the question of what defines hardcore is rarely discussed in the social space. Instead of approaching design by adapting tried-and-true principles to the new format, social games have grown up dedicated to a new religion of A/B tests, metrics analysis and Skinner Box psychology. In many cases, the expertise of professional game designers has been deferred in favor of simple trial and error.

But things change and, 14 months after the start of the boom, the old games are withering, like so much untended virtual wheat. Investment money may be plentiful but an ultimatum is nearing.

The fact is, social games are games and games need game designers. A/B tests and psychological conditioning can only go so far.

Good old fashioned design talent combined with an honest understanding of why certain games work and others don't will ultimately mean the difference between a bursting bubble and an emergent industry.

For social games to succeed, their designers must make a conscious effort to adopt and "make casual" the preceding 30 years of industry design knowledge.

So, to return to the question, what makes a game casual?

At first, it may seem trivial to answer: if a game is easy to play, it's casual; if it's not, it's hardcore. Yet "difficult" is a broadly subjective term that describes many different things. Pac-Man is difficult, but is it hardcore? And what about Tetris? Surely Tetris is casual, yet how can a game that always ends in failure not be considered difficult?

The distinction is accessibility. A game that starts easy is accessible, even if it ends hard. But knowing this doesn't exactly give us any revolutionary insight. To truly understand casual, we must first dig deep into specifically what makes a game inaccessible -- what makes it hardcore.

Six things that make a game hardcore:

Six things that do not make a game hardcore:

What Hardcore Is

Difficult Controls. In the early days of games like Pac-Man and Frogger, control was usually a stick -- there was up, down, left and right and that was basically it. As soon as game controls became more complicated, games were on a route towards becoming hardcore.

Mario 64 is a popular example that illustrates how far controls have gone. Mario's long jump requires two buttons and the directional stick. The move is unintuitive and must be taught to the user. To make matters worse, there is inexplicit timing involved: the user must first run in the desired direction for x seconds, then press and hold the Z button for y seconds before following it up with the A button.

Get it wrong, or out of sequence and Mario skids to a halt or, even worse, stops in mid-air and does a ground pound. x and y are inexplicit; they must be discovered and then memorized. This is hardcore.

Limiting input to a mouse goes a long way towards keeping controls casual, but the lessons of timing, precision and discoverability apply in any context. A casual user has no patience for learning or perfecting interface.

Overwhelming Options. At the simplest level, overwhelming options can be thought of as the number of buttons available to being pressed at any given moment. At a deeper level, it pertains to all of the options available to be weighed when deciding what to do next. The casual user wants to make meaningful decisions, but if the full scope of the decision is overwhelming or under-communicated, it goes from meaningful to frustrating.

For example, even if a casual player understands the functionality and unique utility of eight different but equally balanced guns, deciding which one to use on the spur of the moment can still be overwhelming.

One could argue that the trial and error of finding the right option is simply part of the learning process but this would overlook the fact that casual users lack gaming experience. For a trial to be meaningful, the user must be able to reduce the decision space to a single dimension of doubt, (meaning at most there is only one unknown). When multiple unknowns exist, the combinational size of the trial-space quickly becomes overwhelming. Choices must be gradually layered into the gaming experience.

Prerequisite Gaming Knowledge. If your game assumes the player has played other games, it requires prior knowledge. Even "common sense" gaming standards like picking up a new item will put the old one in inventory, or anything being endlessly respawned is probably required to solve the next puzzle are not obvious unless you are an experienced gamer.

Assuming your casual audience knows nothing of video games seems an obvious thing to do, but in practice is actually very difficult; years of video game immersion can be a hard thing to set aside. Usability testing can be an invaluable asset for spot-checking a design, but the details are often tiny and overlooked. An effective casual designer must learn to live and breathe 'casual' and make the knowledge base second nature.

Abstract Memorization. This was hinted at already, but it is important enough to warrant its own category. Anything that is not directly intuitive and can't be inferred from a typical player's lifestyle, must be memorized. Winning the race involves crossing the finish line first is obvious. Shells shoot forward and bananas go back is not.

At the purest level, this is the difference between: press the A button to jump vs. press the stick up to jump; one is abstract and must be memorized, the other is intuitive and more effortlessly remembered. The more abstract a feature is, the greater the risk it will be forgotten, and, the more features a player forgets, the greater the likelihood of frustration.

Unclear Goals. Any game where the user must figure out what to do next is hardcore. Open-ended or user-defined objectives are one thing, but as soon as the player grows bored with open-ended options, there had better be some clearly-defined goal waiting to be achieved.

Even an implied goal as straightforward as "kill all the monsters" may not be as clear as you think. Casual players want to make interesting decisions, not try to figure out what's expected of them.

Unclear Solution. There is a very careful distinction that needs to be made here. You do not need to ensure that every solution to every puzzle is obvious, but you must make clear what the nature of the solution will be.

For example, four pressure sensors that need heavy blocks pushed onto them is a clear goal with an acceptably unclear solution; all of the parts are known (the sensors and the blocks), but how to get all four blocks simultaneously into place must be discovered.

Unacceptably unclear solutions are those with which even the method of solving is unknown. In the Shadow of the Colossus, the player is given a light-beam pointing in the direction of the next Colossus -- this is a clear goal. But at times, finding a valid route to the Colossus is intensely unclear.

A user trained to locating his target by riding vast distances in a narrowing spiral, will not be conditioned to search out an unmarked climbing foothold in an out-of-the-way location. An unannounced change in solution methods is hardcore.

Summation

The six hardcore bullet points broadly cover most cases of design that make a game hardcore. Avoiding them will help ensure a game that is more accessible. But there is a danger in going too far. There will be those who oversimplify their designs to the point that they are no longer fun. Therefore it is worthwhile to define what may appear to be hardcore but actually is not.

What Hardcore is Not

Challenge. The most common assumption is that a difficult game is necessarily hardcore. This is simply not true. The confusion lies in the language: just as "hot" describes both spice and temperature, difficult describes more than one thing.

If your interface is vague, the game is "difficult", if the objectives are unclear, the game is "difficult", if your game is addictively simple yet impossible to master, it is also "difficult". Difficult describes both accessibility and challenge. Difficult accessibility is bad and is covered by all six bullets in the previous section.

Difficult challenge is good and, in fact, it's the most casual route to replayability. You want a user to feel that mastering your game is a challenge; that each session ends with a new sense of accomplishment. The real trick is in instilling challenge without devolving into one of the six pillars of hardcore design. Tetris manages to do it simply by speeding up the drop rate of the pieces, but most games don't have the luxury of such a straightforward solution.

Trial and Error. As mentioned in the hardcore section, a puzzle with an unknown solution is acceptably casual if the method of solution is known. Puzzles in which the solution set is carefully limited promote a form of trial and error that is not only acceptable, but desirable.

Casual users need to try out their hypotheses and a series of trials that end in success can actually be quite rewarding. The key is to soften the impact of failure. In making subsequent attempts, the casual user should not be required to repeat a significant amount of time or effort. If your game doesn't support an easy turn-around on trial and error play style, it risks becoming hardcore.

It might be worth pointing out that session length is often confused with trial and error turn-around time. Yes, your game should allow the user to come and go with ease, but it doesn't have to limit the entire scope of game experience to a single, repeatable trial loop. In order for games to stay interesting, the experience -- the discovery -- needs to evolve and become more meaningful. If no sense of anticipation bridges play sessions, the game stales and the player eventually loses interest.

Strategy. "Strategy" is another word that has multiple, nuanced meanings. Foremost, the word has been taken to define an entire genre of games. Strategy games are some of the deepest, most complex games available. Strategy games are hardcore.

Strategy also describes the mental process a player goes through while problem-solving a game system. These kinds of strategies are not necessarily complex; hiding behind a wall until the enemy passes and then sneaking up behind him is a strategy.

The fact is, strategy is what makes gameplay interesting; it is the choices players make and the decisions that ultimately pay off in victory. The trick here is realizing just how simple strategies can be.

Any situation that can be validly addressed with multiple actions is strategic. I'll wait for the goomba to come near, then jump on him, is a strategy -- just as is approaching the goomba at speed and jumping over him, or backing off and waiting for it to fall in a hole are valid alternates.

Theme. All too often theme and content are confused. For example, a game is not hardcore simply because it involves an elf with a sword. It's true that many games featuring elves and swords have been hardcore and an association may be developing, but is it fair to claim the elf or the sword is the reason the game is hardcore?

This goes back to the question of prior knowledge, where the question really becomes: does including an elf imply a burden of prior knowledge? In some cases, such as the Legend of Zelda, being an elf implies little more than pointed ears and a green tunic. But in other cases, the implications go much deeper, often implying character proficiencies in agility and magic that could actually constitute a burden of prior knowledge.

Ultimately, you need to be conscious of the messages you broadcast via theme, but understand that theme determines audience segment, not accessibility. Yes, hardcore gamers and young males are two groups with significant overlap, but they are not the same thing.

Repetition. Casual players do not mind doing the same thing over and over again, particularly if some small part of the process is becoming incrementally more challenging. Tetris is a good example, but so is Pokémon. Battling in Pokémon is extremely repetitive, but each enemy is slightly different, preventing the process from stagnating.

The real key to this bullet point is to realize every game is repetitive and that the level of hardcore it's aiming for should directly correspond to the rate novelty is introduced. Therefore if your game is explicitly hardcore, you should introduce larger and more frequent gameplay twists to keep your audience satisfied, while casual games should keep the twists smaller and less frequent. Another way of saying it is: hardcore games are less repetitive, casual games are more repetitive.

Depth / Graduated Objectives. This is by far the most difficult bullet to address, primarily because so few casual games have managed to prove it right. As I mentioned under Repetition, the introduction of new twists and goals is hardcore.

The point of this bullet is to stress that new gameplay is not to be avoided entirely. While it is important to manage the flow of new features presented to the user, it is not always desirable to choke them off entirely. The solution is to be aware of the level of strategic complexity the player is experiencing. If you have a game where some strategies become second nature and cease to be interesting, it's time to advance the gameplay so that new strategies emerge. Failure to do this will cause gameplay to stale and hurts replayability.

The reason why this bullet is difficult to argue is that, in many cases with casual users, replayability is not important. So far, most casual games have been developed with the expectation that they will cease to be interesting in a short amount of time. If the business model supports it (such as online downloadable, iPhone, or games with episodic content) the user actually expects the game will grow stale and factors that in to the purchase decision.

It's only in the subscription and free-to-play spaces where a long-term relationship between user and game is even important. And, as is expected, the biggest difficulty facing developers in these spaces is user retention. But depth isn't just a new set of art assets to collect or a Christmas-themed minigame, depth is new user choices, new gameplay objectives that build on or evolve the previous interaction.

If you discern just one thing from these lists, it should be that accessibility is everything. The ability to identify a popular theme is not a rare skill and successful games can not be built solely on the assumption that people like cute pets or mafia power fantasies. Games must be accessible. Just as popular books are easy to read and popular movies are easy to follow, popular games are easy to play.

If you manage to discern just one more thing, it should be that games need to be and stay fun; as soon as the user isn't making new discoveries, the game is boring and no amount of obligation will keep the user from losing interest.

In Conclusion

I'd finally like to add that although my focus has been on rethinking game designs for the casual space, the points made are equally important in any space. Hardcore may be a badge of honor amongst dedicated gamers but, as more and more people play games, it's worthwhile to reevaluate our assumptions. How many hard-core tropes build honest challenge and how many are simply lazy design that alienate market share? The casual space may have much to learn from its predecessors, but that's not to say it doesn't have a few important lessons to impart of its own.