Feedback Loops and Class Design

A little break from the How I Design series.

I had a conversation with a friend recently who had a hard time understanding the difference between different classes in MMOs, and why some people so heavily favored one class over another when they appeared to be very similar.

He’d played the Gladiator in FFXIV and found it interminably boring, and asked if anyone liked “pressing 1, 2, 3 over and over again”. The answer, “yes”, baffled him, and I think convinced him that MMOs weren’t for him, though I don’t think that’s necessarily true.

In an MMO, specifically the ‘traditional hotbar’ MMO, there’s generally a bit more nuance then “press buttons in order” or “hit all the buttons whenever they’re available”. Most of the time, any classes that use those mechanics exclusively are considered extremely boring. The concept boils down to the class’ feedback loop, or the thing you’re doing when fighting in order to win.

There are a few different types of feedback loops that are popular in MMOs:

The Availability System

This is the oldest MMO class design, and is the simplest. It’s often criticized as “all MMO classes”, although it’s notable that very few such classes exist in modern Western MMOs.

Availability System classes have a variety of abilities that take a certain amount of time to become available after using, called “cooldown” time. A pure Availability System class will press every button as it becomes available, and cooldowns will determine how often they’re available. No secondary resource is required, because time is the only resource used. A common twist on this concept is a passive ability that refreshes a cooldown whenever certain criteria are met, such as a critical hit refreshing a powerful attack. It raises the skill cap of the system slightly, but this is still a fairly old, little-used design concept.

These have fallen mostly out of favor (largely due to the low skill cap), though players will occasionally opt into classes like this when ability systems allow a lot of customization.

The Rotation System

An evolution of the Availability System, a rotation-based class generally has fewer cooldown abilities and usually has a secondary resource. These classes can use abilities far more frequently, but there tends to be an efficient order that is repeated. Skill in this system is determined by completing the rotation in a timely, efficient manner and not losing opportunities to continue the rotation.

A common added feature of rotation-based classes are what are known as “off-GCD” abilities. Essentially, there is a mechanic called the Global Cooldown, abbreviated GCD, that is the minimum amount of time between actions. It exists essentially to prevent key spamming as a successful strategy and maintain the desired pace of combat. An ability that’s not bound by the GCD can be used between other abilities, allowing quick reactions even if the standard abilities are still unusable. Abilities like interrupts are often like this, or certain temporary power boosts. Juggling these in between standard abilities allows a perceptive player with quick reactions a higher skill ceiling.

The Priority System

Priority systems have mostly been relegated to healing classes until recently, but they have had increasing popularity among other class roles in the last few years. The general concept is that for a priority system class to achieve maximum effectiveness, it needs to use abilities both proactively and reactively, so that whichever ability is needed at any given moment is based on the current situation. Generally speaking, this revolves around either maintaining self-buffs, applying and maintaining layers of debuffs on a target, or using/consuming said buffs for a power spike.

Early concepts of the priority system were the purely reactive healing, where there is no set “rotation” and the unpredictability of encounters means that a cooldown-based availability system is less functional. The spell needed by the healer was then applied to the situation at hand, on the fly. This has bled into other class roles, most often tank classes but occasionally damage classes as well.

These sorts of systems tend to be less complex but require more situational awareness, in the case of damage classes often reducing the risk of tunnel vision that rotation-based classes often have.

Feedback Loops

Each one of these types of systems have a built-in feedback loop that appeals to a different sort of player. Rotation systems are favored by players who enjoy memorizing a pattern and then executing it with precision. Availability systems are favored by players who enjoy having a broad selection of abilities to use, and don’t like hitting the same buttons repeatedly. Priority systems are favored by players who are less interested in memorizing patterns and prefer to react to the moment.

For any game featuring classes, where the core gameplay requires a lot of one or a small number of verbs (usually, “fight”), it’s important to develop a functional, fun feedback loop, which requires some understanding of the above systems, or any new system that’s devised.

Without a core feedback loop that works, your class won’t be interesting moment to moment, and while you may have larger systems that make your game fun on a macro scale even if the basic gameplay loop isn’t interesting (EvE Online is a very good example of this), it’s important that this design choice is a conscious one.

Source: Digital Initiative
Feedback Loops and Class Design

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