It's not a Trinity, it's a Duality

I'm sure you've heard the story before, but here's the main point: there exists a "trinity" within MMORPG design that focuses on the tank, healer, and dps roles, clearly illustrated in such mechanics as World of Warcraft's new "auto-party" mechanic that allows players to fill one of those three roles. Some bloggers argue that this design is flawed or overused and that alternatives ought to be found, such as by exploring alternatives to the "trinity" mechanic itself or closely tied-in mechanics such as "aggro."

I argue that the notion of the "trinity" is due to a limited scope of game design analysis: by only looking at games that have implimented the trinity system, the broader view of game design is lost. I take another approach, and argue that the notion of the "trinity" itself is an erronious extrapolation of the core duality of combat: offense and defense.

In combat, there are four possible outcomes:

There are two ways of influencing the outcome of combat: to improve your chances of winning and to improve your opponents' chances of loss. These are the basics of offense and defense.

Consider a historical game without magic: your offense would consist of units specialized in killing enemies, often at the cost of survivng enemy encounters, such as archers, and units specialized in surviving encounters, often at the cost of reduced combat effectiveness, such as heavily armored knights. A combination of strategy (picking the right assortment of offensive and defensive units) and tactics (deciding when and where to mobilize these units) influences the course of battle and leads to one of the four outcomes indicated above.

The problem arises when magic is introduced into a fantasy setting, because the general implimentation of an offensive magical unit is not much different than a non-magical offensive unit (fireballs aren't so different from arrows) but magical defensive units are very different than non-magical defensive units (healing magic is very different than heavy armor). The result is that two different kinds of defenses seem so different that they seem like different roles altogether.

But this is not necessarily the case. Truly, the greatest failing of the 'trinity' has been to differentiate "tanks" from "healers." Consider the following scenario:

An enemy is dealing heavy damage to one target and light damage to many other targets.

The reaction to this scenario in typical RPG design is a tank to absorb the heavy single target damage and a pair of healers: one to heal the tank and the other to heal the rest of the party.

But consider alternatives. What if one defensive character was able to redirect the damage to the party to herself, then restore her health by draining it from the enemy? What if a combination of a character with high evasion and a character that could reduce the enemy's chance to hit worked together to make most of those heavy hits miss entirely, the remainer absorbed by the character that was self-healing?

In this case, is the self-healing character a "healer" because she is healing or a "tank" because she is taking all the damage? Perhaps instead, we can understand her role to be a defensive one, along with both the two-man evading team.

Of course, this example still relies on the mechanic of "aggro" that has been criticised by some bloggers. The mechanic of controlling whom in your party is being attacked certainly does not reflect intelligent behavior and is not at all replicated in player vs player behavior. As a result, many game systems designed to work on an aggro system in PvE suffer greatly in PvP applications.

But games designed for PvP, which do not have aggro concerns, also seem to avoid the entire "trinity" system as well. Consider EVE Online, whereby ships are equipped in defensive roles, with both high damage reduction AND the ability to repair nearby allies. Groups of ships fly together and they all repair whomever is being focused by their enemies. There is no tank: any one of them could become the target and have to "tank." Meanwhile everyone is shooting at their target. Everyone plays both an offensive and a defensive role.

Consider Planetside, a first-person shooter with MMORPG inspiration. Players who wear MAX armor have tremendous defensive capabilities, allowing other players to take cover behind them. But everyone not in a MAX has the potential to be a "healer" and repair the MAX-players (or anyone else). Again in this case, everyone plays both a defensive an offensive role.

Ultimately, it seems, it is not so much the "trinity" itself that is the problem in unvaried game design, but that game design is unvaried. There is no fundamental design concept that prevents an MMORPG to explore player roles beyond the trinity or systems beyond aggro. Indeed, many games do have radically different designs. The real reason the "trinity" is so prevalent is actually a good one: it's a system that many players enjoy and find fun. People want to play trinity-based games.

In conclusion, a bit of a metaphor: the reason football (soccer) is so popular around the world isn't because people are incapable of using their hands, it's because kicking a ball around is fun.