Providing immediate, excessive, multimodal, varied positive feedback on relatively small user actions can instil a sense of competence, effectance, and control over the world even when there is no big challenge to overcome. It also taps into curiosity and surprise with unpredictable variation and unexpected exaggeration.
In the 2007 casual puzzle game Peggle, players have to shoot all orange pegs off the screen using a cannon with metallic balls. Clearing all balls in a level triggers the words “Extreme Fever” flashing on the screen, a firework crackling out of the place where the winning metallic ball fell into, a rainbow appearing, bonus points counting up, and the tune “Freude schöner Götterfunken” playing.
No known instantiations.
A stock trope of first-person shooters like DOOM (1993) are barrels that explode when shot, damaging (and sometimes sending into flight) surrounding actors and objects. Relative to the typical feedback a shot produces in a first-person shooter, an exploding barrel is unusually spectacular and produces less predictable results.
In the physics puzzle game World of Goo (2008), players are tasked to construct edifices of little living goo balls to help them reach certain points in a level. Picking up, moving, placing, releasing a goo ball all come with little forms of rich and not completely predictable multisensory feedback: the goo ball “squeaking”, a snatching sound from a goo ball becoming detached from others, a splashing sound when the goo ball is released and attaches to others, visuals from squirting droplets of goo as goo balls get detached, transported, reattached, the goo ball rolling its eyes, and so on. Overall, this gives the core interaction of World of Goo – moving goo balls – a very “tactile”, satisfying feel.
The “juiciness” of feedback has been described as what makes an interface feel tangible, responsive, inviting, and fresh . Since most game interfaces still reduce the multisensory experience of interacting with the real world into keyboard, pointer, and touch input and audiovisual output, they can quickly lack in the experience of affecting “tangible” change in the world. By exaggerating feedback relative to users' expectations of game interfaces, juicy feedback attempts to reinstate the satisfaction of effectance and combine it with the enjoyment of a type of sensory feedback that is unusual and therefore curiosity-satisfying – like popping bubble wrap, or discovering that you can produce a sound by rubbing your wet finger over the fringe of a thin glass.
Here is how Gray and colleagues  describe it:
”'Juice' was our wet little term for constant and bountiful user feedback. A juicy game element will bounce and wiggle and squirt and make a little noise when you touch it. A juicy game feels alive and responds to everything you do – tons of cascading action and response for minimal user input. It makes the player feel powerful and in control of the world, and it coaches them through the rules of the game by constantly letting them know on a per-interaction basis how they are doing.
Some juicy examples you may have experienced might include:
Good feedback should not get in the user's way while she is still in the process of accomplishing a goal or task. Hence, juicy feedback – which tends to absorb a non-trivial amount of time and attention – is appropriate when the user has achieved the closure of a certain goal or arc: the more involving the feedback, the more significant the closure should be.
Users get accustomed to any kind of feedback quickly, such that the surprise value and sense pleasure of juicy feedback can diminish to the point where a drawn-out celebratory sequence where the user is denied agency may become boring, trite, and frustrating. Consider how you might add variation to the feedback to keep it fresh, or to include a slow reveal of information in the feedback to keep the user interested.
One useful way of thinking through how you might increase the juiciness of feedback is to systematically map out and work through what interaction designer Bill Scott has called ”interesting moments”: all the minute sub-states and steps of a single interaction, e.g. mouse movement, hover, click, initiated drag, continuing drag, hovering over valid target, mouse release in a “simple” drag-and-drop interaction. World of Goo (see above) provides a nice illustration of this in practice.
To increase the juiciness of a given interaction,
|Moment 1||Moment 2||Moment 3-n|
|Visual||Insert visual feedback on moment 1||etc.|
|… variation||Insert possible variations of visual feedback on moment 1||etc.|
There are no established metrics for the experienced “juiciness” of feedback. For competence, use the competence subscale of the Intrinsic Motivation Inventory (public) or of the Player Experience of Need Satisfaction Scale (proprietary, contact Immersyve).
This pattern is industry standard, but not yet empirically validated.