[Experienced MMO designer Brian "Psychochild" Green pulls at the MMO trinity -- Tank/Healer/DPS -- to examine whether or not this pillar of combat design can be pulled apart, modified, or even changed fundamentally.]
Designers, like many people, tend to fall into habits and patterns. Our games fit into specific genres, so they tend to be similar to other games in that same genre. Best practice is to borrow systems that work well in other games. However, sometimes a system gets enshrined into the conventional wisdom; once that happens, we rarely turn a critical eye to these systems and see if they are really meeting the design requirements. MMORPGs experience this type of "inherited design" for many gameplay systems.
One common design in MMORPGs is the "holy trinity" of class roles: Tank, Healer, and DPS (or damage dealers). As most games are about combat, these roles are about how damage is handled: Tanks can mitigate incoming damage from enemies, healers restore damage done from enemies, and DPS classes do damage to enemies.
Characters often require specialization: a superb healing class may not be able to do good damage without a significant change that hurts healing ability, or they will often not want to do damage because they need to save their resources for healing others. This trinity of classes forms the basis for most group-based encounters in a game.
There are other roles of characters possible in these types of games. For example, "crowd control" (CC) classes can temporarily take enemies out of the combat, and "buffer" classes can use abilities that enhance the abilities of other classes.
These additional roles are often combined in a class with a primary role: a healing class might get good buffs, a DPS character may be able to control extra enemies, etc. These other roles can also be taken care of by the core roles: a secondary tank can keep multiple enemies occupied if crowd control is not available, for example.
Finally, the DPS role sometimes has specialized categories: melee, ranged, single-target, area of effect (AoE), etc.
Our design goal for this article is to look at alternatives to the trinity design. First, we must understand the details of the trinity design, what design goals it accomplishes, and what type of design could replace it. For this discussion, we'll make a few assumptions:
For this article, design is the only focus. Technical limitations tend to be specific to each game and therefore of limited use in a discussion. Other vital issues, such as community management of player expectations, are also beyond the scope of the article.
It is useful to look at the history of character classes in RPGs to trace the origin of the trinity design. Classes were part of the first well-known RPG, Dungeons & Dragons (D&D). Each character had a class that determined his or her abilities: equipment that can be used, hit points, magical ability, etc.
Each class was based on a fantasy archetype, but without explicit roles; there was no rule that a Fighter could only absorb damage (be a Tank) and not be an awesome machine of death (be DPS). Each class had signature abilities, but statistics and options allowed characters to fill a variety of roles despite their class.
Over time, certain patterns of gameplay emerged: for example, the physically fragile low level wizard might prefer to be protected by the heavily armored fighter instead of rushing forward to engage enemies on the front line.
The MMORPG EverQuest (EQ) had the concept of classes and started the focus on the trinity of core classes. Inspired by a text MUD that was based on a D&D game setting, EQ had a class design that borrowed heavily from the older D&D system.
The core trinity of roles rose to prominence in high end raiding: a character tanked the boss, healers had to keep the tank alive, and other players hurt the boss without drawing too much attention to themselves. Each class had a single role it did well: Warriors were always Tanks, Clerics were always Healers, etc.
World of Warcraft (WoW) borrowed from EQ's class design and refined it. It added different talent trees that allowed a single class to specialize. WoW's expansions allowed some classes to fill multiple roles through talents; a Druid is able to become a Tank, a melee DPS, a ranged DPS, or a Healer based on equipment and talents chosen. A single character is usually expected to only fill a single role in one encounter.
Paper RPGs have been developing during the years as well. The fourth edition of D&D comes full circle, and the venerable paper RPG has been inspired by MMORPGs. In the latest edition, classes have gotten explicit roles as part of the class description, although it doesn't quite use the same roles as the trinity.
Other systems have gone away from classes and roles; for example, GURPS and the White Wolf's World of Darkness have had more flexible character development systems that rely more on lists of skills that any character can take rather than on strict classes and roles.