There are many possible reasons for a game being compulsive. Player personality type, motivation driven by a game genre or licence and social influence all affect the desire to continue to play.
Of course, another possible reason is that the game has been designed to be as compulsive as possible. On one hand we could say that the game has been engineered to be as compulsive as possible, but this sounds malicious, almost as if it’s fighting against the players’ free will. On the other, we could argue that the game has been crafted to be addictive, this sounds much more positive and in alignment with an optimal player experience. Either way, games are created with the intention of being as good as possible, and one way in which to create an addictive game, is to design an engaging game loop.
The game loop is a sequence of events which the player must repeat, with the hopeful aim of experiencing entertaining gameplay. For example, in many online social games a typical game loop might be; 1. Buy land; 2. Buy items to put on land; 3. Earn money from land; 4. Spend money on land. But just because the game loop repeats, it does not mean that the game is boring.
Five rules for smarter game loops
Wooga’s Henric Suuronen suggests that game loops can become more intelligent by adding "smart-depth" - more to learn as the game unfolds - and proposes five rules for creating better and more compulsive game loops:
- Add a new layer of subtlety on top of the existing game loop, don’t add an extra step.
- Novice players should not need to care about smart-depth.
- Smart-depth should not require hand-eye co-ordination, but instead use strategy; there should be more than one solution to the problem.
- Players can engage on a basic level, but later engage on a better level.
- After completing a task once, the game should reward the player for an even better solution.
But how does this work in practice?
The Game Dev Story example
In late 2010, an iOS game emerged from Japanese developer Kairosoft in the west which received wide acclaim. Game Dev Story is a management sim that puts the player in charge of a game development studio, and follows the studio’s 20-year career from humble indie beginnings right through to making AAA hits. In particular, many reviewers and feedback on forums commented that players could not put it down. So what did Kairosoft do right?
When the game first starts, the initial dialog introduces a secretary character who is there to help “whether you are an expert or this is your first time”. It immediately makes players aware that smart-depth is present, that this is a game designed for replay and offers layers of complexity.
The main game loop then begins. It's mostly concerned with assigning your various staff to work on components of the game: design, coding, graphics and audio. Although there are quite a few steps in the game loop, each one requires a fairly low degree of decision-making, ensuring both rapid progress and making the player feel like an effective manager. Smart-depth is added by allowing the player to choose various attributes for their upcoming game, but not overly punishing them for poor decisions. For example, a pirate adventure game will probably perform better than an educational history game, but the game does not stop players from playing further merely because they've made bad choices through lack of experience. Instead, they are softly encouraged by giving the idea that their choices could have been improved upon, giving them actionable feedback on how to improve and encouraging replayability.
In the loop
At various points, staff members will try to improve the game’s quality by focusing their creative talent on a single aspect, such as the sound. This is essentially a game of chance, but you can invest valuable research points to increase your odds. These chance-based elements add the perfect counterpoint to the logical decision-making processes that take place elsewhere in the game. Of course, I'd like to see a dialog box appear which states “We could increase the quality of our game through playtesting, can we run a session?”, but it doesn't exist. Let's hope for Game Dev Story 2.
Once all game-influencing decisions are complete, the final success may be measured by your number of fans, studio income, magazine reviews or game sales. It’s in this last area, game sales, where Kairosoft has been particularly clever, leading to one of the most likely factors for the game’s compulsive nature. There’s no clear exit point.
No exit
For many gamers, it’s more likely that they will stop playing at the end of a level rather than in the middle of a level. However, in Game Dev Story, the end of a level is somewhat blurred, as once your game in development is complete, rather than be rewarded with the sales figures immediately, you have period of time where you see your game's sales figures gradually increase. You're not inactive, however, because you'll be taking on contract jobs or starting another game development project so your staff don't lie fallow, effectively starting a second game loop before the first has finished. This overlap in game loops removes a natural exit point from the game, making it much more likely that you'll continue to play. Forever.
OK, so forever is perhaps stretching the point, but when combined with the game’s theme, pace and smart-depth potential, it really is very easy to play this game in long sessions. Not bad for a mobile title.
A cautionary word, however: at some point players will quit the game, and by not creating a clear exit point, it can make the returning entry path more difficult. It could even create a barrier to entry so great that it pushes players away for good. Disguising your exit points may encourage players to play longer, but it could also blur their re-entry point.
Graham McAllister is director of game usability lab Vertical Slice. Read and follow Graham's other columns on his topic page.