The sliding scale of optional rules in RPGs

“It is a truth universally acknowledged that though all rules are optional, some rules are more optional than others.” — Aristotle.

Back in the very early middle Eighties, E. Gary Gygax occasionally published a peevish piece in Dragon magazine in which he animadverted against people playing AD&D wrongly, for example by using THAC0 instead of specifying which line of which combat matrix an NPC or monster attacked as. “If you don’t play by the official rules” he told us “you aren’t playing the Dungeons & Dragons™ game!”. We responded with derisive laughter, and since then no-one has threatened again to send the RPG police around. Since then all rules in all RPGs have been optional. But in practice some are a lot harder to opt out of than others.

At one extreme you have rules that you can simply ignore without that making any difference to anything else in the game. For example the rules in GURPS for a character’s height and weight in feet, inches, and pounds as limited by that character’s ST characteristic and build disadvantages. These only make sense at all if your character is a normal human, and the main point of GURPS is that characters needn’t be, but fortunately you can just turn the page, leave spaces blank on the character sheet, and ignore those rules. Nothing else in the game is affected in any way.

Then you have rules that are properly optional, in that they aren’t completely pointless, but about which you can make a simple clean choice to use the option or not and it will change the game in a way that you might well want or not, that is clearly explained at the point where you choose it and properly carried through all the systems affected in the game’s design. An example of that would be the choice of “Purist” or “Pulp” mode in Trail of Cthulhu, or the combinatoric choices of “Stakes”, “Dust”, and “Mirror” modes in Night’s Black Agents, or the choice between the basic combat system in GURPS Spaceships and the tactical space combat system in GURPS Spaceships 3 Warships and Space Pirates.

Then you have rules that are optional in the sense that they deal with an aspect of play that you might not include in your adventures. The very first paragraph in Chapter 8 of ForeSight (the spaceship construction, operations, and combat rules) is a designer’s note urging you not use them because (i) little roleplaying occurs in space combat, (ii) space combat is too deadly, and (iii) spaceships are too expensive for PCs to own them. That’s all very well for a subject that doesn’t arise in most games, but it is a nonsense for a subject that has a big part in most campaigns in the genre that the game is ostensibly designed for, as for example combat rules in most RPGs.

Finally, you have rules that are optional in the sense that no-one is going to send the boys round if you don’t use them, but that you can’t just switch off without either (a) tracking down and patching a great many references to them and interactions with them scattered throughout the rules, or (b) designing yourself something to replace them. For example, the injury multipliers for different damage types in GURPS are not optional rules except in the trivial sense that every rule in every RPG is optional.

Until someone wants to lift you (with strength, magic, technology, etc.) at which point you need to know the total weight they’re trying to lift. Yes, you can make assumptions about how much people weigh, but it’s not quite as simple as ignoring them.

I think I’d call GURPS tech levels “properly optional” or “aspectedly optional”: if you’re not moving from one technological context to another, you can say “all my TL skills are appropriate to the campaign tech level, and I’m simply never going to read those rules”, and in most games there’s no particular call for anything more. Similarly non-standard gravities for an Earthbound game.

And then if you’re a centauroid robot or a psychic blurberry muffin — which GURPS supposes that you might be — those rules give absurd answers.

Sure, but you need something to put in the “weight” box at that point. So it’s not quite “leave spaces blank”.

Next time you tell me that in GURPS every rule is optional except for “roll 3d6 and get a target number or under”, I am going to remind you that you wrote that.

The height and weight rules in GURPS are fully optional in that you can (and sometimes have to) just ignore them, you do not have to repair any effects on any other rules, because there aren’t any. So for instance if your character is a six-legged stainless-steel robot centaur, or an ant-themed superman one foot tall who can lift five tons, the rules will produce nonsense. But you can blithely ignore them and write in whatever seems hoopy — or leave blanks — with no need to patch other rules.

EGG’s point, though, was really about protecting his trademark - the complaint was that you could go along to a convention, sign up for a D&D game, get to the table and be told “We are playing D&D, but we use the hit locations from Aftermath, Critical Hits and Fumbles from Runequest, and a Magic Points system that we wrote ourselves based on a fanzine article we read” - and if every role-playing game (or at least every Fantasy role-playing game) could be described as “Dungeons & Dragons” then TSR would have lost control of it’s TM…

I think that what EGG really cared about (quite separately from any commercial considerations) was the tournament/sport side of RPGs – the idea that you could have a whole bunch of groups playing the same adventure, and you could determine from how they did who was the best player.

To do that you absolutely need a single rule set applied consistently, just as you do in any other competitive game.

This is essentially alien to the way I play RPGs, but it mattered to him.


There are people to whom that matters, but I find them rather odd. When I was running game conventions, we would periodically get people from a group that called themselves “Raven” but who James Wallis described as “The Continuity RPGA.” Their idea was that they would run all our tournaments for us and get free memberships and attendance expenses. They were nonplussed by the answer “No”. Not even “No, thanks” just “no.”

Right. If you play rpgs competitively with players at this table vs. players at another table to see who best beat the adventure, then rule consistency across all tables matters.

At the other end of the spectrum, there was a GM at local conventions who would advertise his games as X even though it was really his own homebrew system (superficially similar to X). He did so because X had lots of fans and the pool of players who want to play homebrew systems is much smaller. So I have some sympathy for the “If it’s not D&D, don’t call it D&D” argument, but we have to recognize that what is or isn’t D&D is not black-and-white.

What has become clear is that EGG was a very different roleplayer to the Braunstein playing groups that he learnt the hobby from…