23 January, 2010
One of the things that new designers should learn is the fearsome power of feedback in gameplay. Great games use feedback to guide the player, letting them master the skills necessary to master the games. With great design comes great power in the form of the feedback loop. For example, a feedback loop can help advance a game; having more units in a strategy game usually allows you to win more battles, leading to the final victory faster.
But, there are also dark sides to the feedback loop when it doesn't start properly or if it becomes self-reinforcing. In this case, the feedback accelerates the loop. The RTS example can turn into a self-reinforcing loop if there is no way to overcome superior numbers in the game through game features like defensive structures. In this case, the player who builds the most powerful side first and plays at least as well as his or her opponent will win.
So, let's take a look at some of the feedback loops in games in more detail.
Feedback is fundamental
All games provide some form of feedback. Graphics or board layouts change, sounds play, items are shifted around, numbers are increased or decreased, etc. Feedback gives the player the information necessary to make decisions on how to play.
Expert designers use feedback to help the player progress. The recent Mario games are usually listed as a prime example how to use feedback to guide the player; give the player a block to hit to get a new ability, and give them a shiny goal to reach using that new ability. Player gets rewarded and learns the basics of a new ability. The player will be expected to master the ability as the game progresses.
Feedback loops come in a lot of other forms as well. In an FPS, the player could be rewarded for more precise aiming at vulnerable locations (HEADSHOT!) In an RPG, the player might be required to gain more levels in order to tackle a higher level enemy. In an RTS, a player who built a stronger economy will most likely be able to build a stronger army (assuming the player who build a small army faster doesn't attack when the economic player is defenseless!) Note that feedback loops happen at different scopes. At a very fine level of detail, a small action such as aiming more precisely in an FPS can help you in a small way. At a larger level of detail, gaining more levels in an RPG can make content easier, even though "gaining levels" requires a lot of individual player actions and decisions.
"Feedback loop" is somewhat of a tautology because feedback is always part of a loop. In communication, I say something and you respond to that with your feedback (verbal and non-verbal). In a game, you make a decision and preform a game action, and the game changes based on what you did. Feedback requires interactivity, and games are all about interactivity, which is why feedback is important for a game designer to understand.
The loop part is important to emphasize, however, because it can help a designer think about how feedback works. If the player understands the feedback as it relates to his or her actions, then the game is much more enjoyable. However, if the player does not understand the feedback, this can lead to frustration as an effect seems to have no cause. For example, if the feedback happens a long time after an action is taken (or not taken), this can be really frustrating to the player. A prominent example of this was in some older adventure games, if you did (or did not do) something early in the game it could result in a problem much later in the game, potentially making the game unwinable. If the player has to rely on external sources to avoid such problems, this can diminish the game.
The stalled loop
One problem with a feedback loop is if it has a hard time getting started. For example, if you need a power-up to preform an action but you need to do that action to get a power-up, this can stall a feedback loop. For example in RPG games, if the initial monsters are too hard for a player just starting and thus the player cannot earn experience from defeating monsters, it is hard to gain the levels necessary.
An example of this is found in Lord of the Rings Online's latest addition: Skirmishes. The soldier you get to help you starts off very weak. Tackling content that seems appropriate will actually be much harder because your soldier will not be powerful enough. In order to get more power, you need to earn skirmish marks. To get the marks, you have to succeed in skirmishes. Once you get a powerful enough soldier, collecting the marks becomes easier and completes the feedback loop. However, it can be hard to start the loop in the first place.
The self-reinforcing loop
The opposite of the stalled loop is the self-reinforcing loop. This is when the results of a player action make subsequent actions easier (or sometimes harder) to accomplish. Going back to our RPG example, we might find that getting into a few more random fights increases your level faster and makes it easier and faster to fight other enemies. You advance faster from killing more enemies, giving you a higher level, making it easier to kill, etc. This type of loop is usually called a positive feedback loop.
Sometimes the loop makes things harder. For example, dying in a game where you lose all your possessions can be a negative feedback loop. You might grab a spare set of equipment to go try to reclaim your lost items, but with less powerful equipment the same situation that caused you problems in the first place may be even more difficult to overcome. Eventually you might run out of options and be completely unable to get back to your original level of power without abandoning the situation.
The terms "positive" and "negative" shouldn't be used as a judgment of the desirability of the loop. A positive feedback loop where someone winning will most likely keep on winning can lead to a really frustrating game. Alternatively, a game where a negative feedback loop makes it harder for a winner to keep the lead can lead to more dynamic and interesting game, even if the player in the lead gets frustrated from being dethroned at the wrong time.
Loop with care!
So, what feedback loops have you noticed in games? Which ones do you think are good uses of feedback, and which are poor?