I did that right, right? Is the axe I just made actually in my inventory? Is this action adding to my enchantment abilities?
Whether the feedback is in the form of sound coming off of a virtual golf club, the omnipresent experience bar in an RPG, or the flash of red simulated blood in the vision of a FPS avatar, players need to know how they're doing.
Our innate learning and conditioning mechanisms. Feedback that occurs directly after (200 to 400 millseconds) or midway through the completion of an action leads to the formation of the strongest associations between action and outcome.
Interestingly, simultaneous timing of feedback with the onset of an action does a poor job of facilitating associations. (See Figure 3).
Back to goals... For medium and long-term goals (completing a level, or the game) feedback on progress can drive further engagement and eventual accomplishment.
This means that players who get feedback will want to play more.
Figure 3: Examples of good (A and B) and bad (C) timing between player action and game feedback.
These animated spell and item icons across the bottom and top of my screen sure look cool! See the particle effects on my Ice Storm spell... Wait -- is someone attacking me?
As sensory and informational clutter increases, the gamer's ability to find and evaluate important stimuli diminishes greatly. This means that designers should strive to maintain a level of simplicity across all aspects of their games (from UI to HUDs).
Again, there are inherent limitations on how much information we can parse at any moment: As detailed in the discussion about the first characteristics of tasks that invoke Flow, we are limited in how much information we can process. Cluttered visual fields disrupt information processing. These disruptions can then negatively affect goal comprehension and rule learning, which ultimately affects Flow.
How can game designers address extraneous information? HUDs and in-game menus should be as simple as possible (e.g., Dead Space or Fallout).
Game skills or options should only be included if they are relevant to the story of the game or are purposefully being used by the developer to push artistic and technical boundaries.
Tasks that induce Flow states tend to have concrete goals with manageable rules, goals that fit player capabilities, clear and timely feedback on performance, and are good at eliminating distractions. If game developers are able to include design considerations that take these characteristics into account they will drastically improve player engagement (and likely game sales).
The example design considerations that I provided for each characteristic are just that: examples. The same can be said for the psychologically-based rationales I provided. Depending on the type of game a developer is making, and whether it is high- or low-concept, different ways of addressing these characteristics are eminently possible -- just as there are many more psychological factors driving how each characteristic contributes to Flow.
It's also worth noting that, for the most part, good game designers and good game companies are already explicitly (or implicitly) taking these Flow characteristics into account.
In the end, I only hope to provide developers and designers with some food for thought on improving player engagement. It is up to those involved in creating games to decide how best to apply this information.
Flow: The Psychology of Optimal Experience (2008), by Mihaly Csikszentmihalyi, published by Harper Perennial Modern Classics.
Working memory (1992), by Alan Baddeley, published in Science.
Cognitive fit: An empirical study of information acquisition (1991), by Vessey & Galletta, published in Information Systems Research.
Effect of goal acceptance on the relationship of goal difficulty to performance (1984), by Erez & Zidon, published in Journal of Applied Psychology.
Emotions and athletic performance: Individual zones of optimal functioning (1997), by Yuri Hanin, published in European Yearbook of Sports Psychology.
Conditioning as a function of the time between conditioned and unconditioned stimuli (1947), by Gregory Kimble, published in Journal of Experimental Psychology.