Saturday Morning Adventure Dev Diaries #4: Design Symmetry in RPGs

Hey all, in this Saturday Morning Adventure dev diary I wanted to talk about something a bit less direct than just the mechanical systems of an RPG, but more a particular design philosophy behind RPGs, that being design symmetry.

So what is it?

I'm glad you asked, imagined reader. Design symmetry means when the design of a game applies in the same way to two different things somehow. Here in particular I'm talking about symmetry between how player characters and non-player characters are mechanically treated in the rules. In a symmetric system, a player should be able to point to an NPC and say "I want my character to do that", and it should be possible within the rules. Whether the GM lets them is another story.

For example, in D&D 5e the NPC mechanics are somewhat symmetrical. NPCs can make attack rolls, ability checks, and saving throws in exactly the same ways as PCs. The ways in which they interact with the game world are symmetrical. However, their creation is asymmetrical. You don't typically create an NPC in the same way as a PC, and this is broadly a good thing in 5e. A lot of the features granted to PCs would just be wasted space in an NPC statblock as they would never be used, like features that only have a function outside of combat.

Additionally, there are plenty of features that are frequently granted to NPCs that PCs never get access to in 5e. For example: legendary actions, sizes other than small and medium, size-based hit points, and abilities that have a random chance to restore each turn.

The Pros and Cons of Design Symmetry

I'll do my best to summarise a couple of the benefits of implementing design symmetry or design asymmetry here, at least from my perspective. Now, please bear in mind that I'm really making a lot of this up as I go based on my own thoughts and theories, so I might be totally off base with some of my conclusions. If you find you disagree with my deeply on any of my points, please let me know. I'm still learning, and I welcome any new viewpoints.

Point to Symmetry: Encounter Balancing

Symmetrical design makes balancing encounters fairly easy. As long as you have some way of measuring the relative strength of player characters (levels for example), then you can balance a group of foes against them easily by just using the same metric to evaluate their relative strength.
Of course, this presupposes that all character builds that can be made to fit the metric are the same relative strength - that is, the metric of choice is accurate. But when using levels as I mentioned earlier, this is clearly untrue. A minmaxed 1st-level Fighter is probably much more threatening than a 1st-level wizard that dumped intelligence and took proficiency in animal handling.

Point to Asymmetry: Retaining the Narrative Perspective

In an asymmetric system, it is possible to design the mechanics in such a way that the perspective is always the same. What do I mean by this? Essentially, you can design a system where everything that is happening can be framed from the perspective of the players. The main example of this is an RPG system where all rolls are made by the players - rather than an enemy making an attack roll against your Armour Class, you make a defense roll against the enemy's Hit Class. Now, of course, you can't really use this 100% of the time, it would break down whenever an NPC tries to mechanically interact with something in the game world other than a player character. However, these cases tend to be fairly rare, and when they do happen a lot of GMs end up just hand-waving the outcome. I mean, when's the last time you heard your GM say something like "the librarian makes a History check"?

It is noteworthy that no matter how this sort of system is implemented, by definition it creates design asymmetry between the PCs and NPCs.

Retaining a single perspective during storytelling can be appealing, but is certainly not always that important when it comes to roleplaying games. It will likely be a more desirable feature in RPGs that are designed to tell very particular stories, and less so in more general-purpose RPGs. The effects of having a single narrative perspective are definitely rather slight, but when used effectively can work to inform the ever-ephemeral "feel" of the game world.

Point to Symmetry: Ease of Creating NPCs

When you design NPCs in basically the same way as PCs, it tends to be a pretty straightforward process to create them. This can streamline the work done by the GM, as it simplifies the process of NPC creation into making the key choices about who they are and what they can do, rolling some stats, then following a well-established method to create the NPC. Streamlining the mechanical side of creating NPCs allows the focus to shift towards creating narratively rich NPCs, which is beneficial to the experience of actually playing the game.

Point to Asymmetry: Mechanically Interesting NPCs

When you don't have to design NPCs in the same way as PCs, it allows you greater freedoms to create characters that can do things the PCs simply cannot do within the established rules. Breaking from the conventions laid forth within the character creation pages can lead to more interesting NPCs when it comes to their actual gameplay.
Perhaps you want to add some ability to an NPC that would simply be too powerful for a PC to have, which is balanced in combat by the greater number of PCs - the classic boss fight style. Maybe you want to give an NPC a simplified trait that would require more fleshing out mechanically if used by a PC - like a magical NPC in a largely non-magical setting. Rather than having to write out an entire magic system you give them a small list of special abilities for combat and hand-wave the rest.

Point to Symmetry: In-World Consistency

Symmetry enforces the rules of the game world to be consistent between player characters and other characters in the world. This has the potential to lead to more "realistic" worldbuilding, and a more grounded story.

In Summary

Design symmetry is probably an aspect worth considering when designing a game, though the differences tend to be fairly subtle in RPGs. Personally, I don't think persuing either doggedly is the right approach. I tend to believe that a base system designed around symmetry works well, but enforcing it fully is both detrimental and impossible. Enforcing all NPCs to be created in precisiely the same manner as PCs would clearly waste a lot of time and writing space, but having them treated as entirely different objects in-game would usually be pointlessly complex and hard to use. And well, this is tabletop games, if someone wants to change a system in your game when they play it there's literally nothing you can do to stop them.

Now I've talked about design symmetry in quite a particular topic here today, but it is a concept that can be applied to many aspects of game design. So what exactly was the point of this post? Honestly I'm not sure, I may have forgotten what my intent was when I started writing. I guess it just seems like an interesting topic to me, and feels like something worth considering in the broader sense as I work on SMA.

Now I've talked about design symmetry in quite a particular topic here today, but it is worth bearing in mind that this concept is more of a design philosophy rather than a concrete set of rules when it comes to the informing the mechanics of an RPG. So what exactly was the point of this post? Honestly I'm not sure, I may or may not have forgotten what my intent was when I started writing. The post was initially sparked by remembering that variant rule that was presented in an Unearthed Arcana that changed D&D into a system in which the player's would make all rolls. I got to thinking about whether that sort of system would work in SMA, and tried to generalise my thoughts around the topic. I really want to get the fundamental feel of SMA right, and considering design symmetry is one way to get closer to what I want. Symmetry will affect many aspects of the design, in particular whether it feels more like a narrative experience or a game. I guess it just seems like an interesting topic to me, and feels like something worth considering in the broader sense as I work on SMA.

Generally when it comes to Saturday Morning Adventure, I'm shooting for a symmetrical system. However, my main motivation in doing this isn't really for any of the reasons I mentioned above. I'm trying to do it because I want the character creation tools to be very robust and allow people to make all sorts of characters using it. For every feature available to player characters, design symmetry forces me to consider that feature being used against the PCs as well. At the end of the day, PCs are not NPCs or vice versa. They serve very different rolls in the narrative. But being conscious of when you treat these two different actors equally or not can be an important feature of the game's design philosophy.

Well that was a load of bullshit, huh. Helpful? Probably not. Interesting? Maybe? Did I have fun writing it? Hell yeah. The next dev diary is either going to be on the magic system or skill system in SMA, I hope to see you then!