The aforementioned principles are important for any stage of the game, but what if the game has a more open world structure rather than a fully linear experience? How is a designer supposed to be able to guarantee that a player has been properly exposed to and taught how to use necessary gameplay elements before a master challenge when he has complete freedom to roam anywhere in the level?
The answer lies in a combination of the two, where the level structure tapers into short linear sections of gameplay, and then opens back up into a more expansive environment offering freedom of exploration, movement and choice. The important thing is that the linear section allowed the designer to teach the necessary skills in a controlled environment before setting the player free into the world.
Both levels are quite open at first glance, but the way they are structured forms a series of tapering linear moments with the contrasting sense of open world freedom.
Games such as Metroid Prime or Resident Evilhave a similar structure to them; both the mansion in Resident Evil and the Ruins in Metroid Prime contain a large network of interconnected rooms, creating a very large environment with a lot of freedom of movement and choice.
What is implemented by the designers, however, is a lock and key system, where the player is barred access to rooms with certain locks until he has found the right key; in Resident Evil this is quite literally the case, where one key will work on ten different rooms in the mansion, and finding the next key will open ten more. In Metroid Prime, the doors are only openable by specific weapons that the player must obtain.
The player is left with room to breathe and significant amount of choice, but out of all the available options, the player is forced to find the specific item that will allow further progression, and the path to this special item is exactly the tool the designer needs to ensure learning has taken place.
"…the game doesn't explicitly tell you to go south. This is not accidental, and is the main way the game communicates. Modern games tell you 'go south to get your sword'. Link's Awakening simply provides information and lets the player use their common sense and logical thinking to decide what to do next." - Starting the Perfect Adventure – Link’s Awakening, by Matt Arnold
The best level designs guide the player indirectly with signs and points of interest that catch their attention and pique their curiosity. In games like Rayman Origins, the clear simplicity of always travelling from left to right is enough to keep players constantly aware of their required destination. It was important in Rayman Origins to reduce the amount of forced backtracking to not confuse the player, and every level of the game contains progression from left to right.
In games like Half-Life 2 and Portal 2, the player is guided through characters, dialogue and environmental cues that attract attention, and give the player intrinsic motivation to seek them out and discover what the level has to tell them, but they are never taken out of playable situations for the sake of guidance or storytelling.
The player has a limited time to slide down and jump from the wall to collect the coin before the bubble descends into the dangerous water; an obvious risk, with a clear reward.
Rewards in games are essential for providing a positive feedback loop and, in the process, encouraging the player to maintain their interest and engagement in the game world. Rewards function essentially as catalysts of micro flow; by properly rewarding successful sequences in the game system, the player is satisfied, proud and motivated to further this feeling of accomplishment and ultimate satisfaction. The game must proportionately reward the player, however, for the level of challenge they have overcome, so as to not lessen the significance of the feeling of triumph the player experiences.
This is described by the simple equation below, from Anjin Anhut's article Having a Satisfying Conversation.
"Challenge - Support = Accomplishment… Accomplishment + Reward = Satisfaction"
It is becoming a trend in modern games to extensively hold the player's hand throughout the experience so as to maintain a proper grip on the difficulty of the challenges and prevent the player from becoming unable to progress. While it is undeniably useful to keep a close eye on the player and guide them through rational level design, the more the player is supported by the game system, the lesser of an impact the successful completion of a challenge will have, ultimately bringing the player a lesser sense of accomplishment.
If a child rides his bike while his father is holding it in balance, he will not truly have overcome the challenge of riding a bike, hence it will feel less satisfying. However, that moment when his father releases the bike and allows him to take full control is when he feels a true sense of accomplishment.
The player is awarded an Electoon for reaching the end of the level. 150 Lums earn the player their second Electoon, and for 300 Lums they can even have a third.
In a blog post entitled Extra Credit!, by Edmund McMillen, game designer and artist on the indie game hit Super Meat Boy, he breaks down the core concepts of risk and reward from older games such as Pac-Man and Super Mario Bros, and eventually analyzes the way he has applied these models to his own game.
The core concept is: the greater the risk, the greater the reward; hard-to-reach collectibles tend to be the most valuable, and a good level designer will make sure to provide clear signs to the player from the start to give them a obvious indication that the path to the reward is perilous.
Risk and reward ultimately needs to come down to player choice. As game designers, we should not impose many choices on the player, but rather we should provide them with an array of opportunities and give them the chance to gauge their own skill and take the risk for the sake of the reward, and it is our job to ensure that their efforts are properly rewarded.
Simply being rewarded for completing a challenge, while somewhat satisfying, by itself can leave players wanting more of a sense of accomplishment. Therefore, a reward system which is based on how well the challenge was completed provides the player with a quantifiable reward that sums up their skill level in a way that allows them to understand that they were not perfect, and could potentially improve if they are interested in doing so.
These "measurement achievements"_ provide intrinsic motivation, a drive to perform better to achieve a higher score for a sense of personal satisfaction. The artificial ceiling that is created when restricting the measure of the rewards the player can earn, which once reached leaves a sense of no perceived possibility to exceed the level of performance displayed, can have the downside of disinclining the player to revisit a specific piece of gameplay, ultimately killing replay value.
By making the maximum Lum count in Rayman Origins higher than the highest value associated with a physical in-game reward, from the player's perceived standpoint, the sky is the limit, and it is up to them to search every annex of every path in the level for the last hidden Lum that will increase their previous maximum count by one, leading to far more replay value than simply providing "three stars", as is done in smaller more casual games such as Angry Birds or Cut the Rope.
The game celebrating the player’s achievement in the form of a disco party; loud music, bright lights and groovy dancing help to praise the player for a job well done.
While it is easy to fall into the position of saying completion achievements should be avoided as much as possible and replaced with measurement achievements, it is important to recognize the significance of rewarding the simplest form of completion for the sake of validating a player who made it to the end.
The Electoon system in Rayman Origins does a decent job of combining the simple completion reward with deeper, more measured rewards. At the end of the level the player is rewarded with an Electoon. When he finishes with enough Lums, he is given a second, and a third. The player is given the opportunity to earn greater rewards through better performance, but a reward is still available for the most basic form of completion.
"A lot of games are stingy with their rewards, especially the emotional rewards, which is kind of stupid because they don't cost anything. If you give too big a treasure at the end of a quest, you'll have to rebalance the rest of the game, but there's no harm in giving big emotional rewards. When the player does well, celebrate!" - Ernest Adams, The Designers' Notebook, October 2010
Ernest Adams makes a fascinating argument about the significance of emotional rewards for a player. It is always important to provide positive feedback all throughout the course of the game, and not all rewards need to come in the form of something tangible; sometimes a simple sound effect signifying the successful chaining of a string of enemies can be reward enough to raise the player's spirits before trudging on with the rest of the level.
In a match of Marvel vs Capcom 3, the number of chained hits are counted in large satisfyingly bright letters across the screen, and when pulling off an especially tricky move, the player is rewarded with text such as "Great!", "Viewtiful!" or even "Dude!". These mean nothing tangible in the game world, but they have the same emotional impact of a crowd cheering at a football match, and drive the player to continue succeeding.
The end-of-level score screen in Rayman Origins is a perfect example of extreme emotional rewards: the player must collect 300 Lums in a level to unlock two available Electoons -- valuable items that allow them to progress further through the game. However, it is always possible to collect more Lums than is required.
When the player reaches 350 Lums in one level, the score screen literally celebrates the players' victory; confetti is thrown in the air, a giant gold medallion flies on screen, disco lights flash, and all the characters start dancing to funkadelic disco music. The game truly makes a celebration out of succeeding, and it manages to provide a real sense of accomplishment solely in the form of emotional reward; the medal means nothing in the greater scheme of things, but the way it is celebrated makes it feel far more rewarding.