tldr: Jargon always has a complexity cost, but you can put effort into making a concept more accessible, and it's especially valuable to put that effort in for terms that you'd like to be used by layfolk, or that you expect to be used a lot in spaces where you expect lots of layfolk to be reading/participating.

I. Lessons from Game Design

Magic the Gathering deals a lot with complexity. Each year, new abilities and rules are added to the game. This gives experienced players the chance to constantly discover new things, but it comes with some issues.

First, it makes the game harder for new players (the game kept growing more complex over time, raising the amount of information a new player had to process at once)

And second, even for experienced players: each instance of complexity is a cost. Players (both new and old) can only handle so much, and some forms of complexity are less fun than others. (For example, forcing players to do a lot of book-keeping, rather than letting them make interesting strategic decisions)

Six years ago, their creative director wrote about a new paradigm of Magic design. One of their solutions was to pay careful attention to how they spent complexity points in ways that affected new players.

Three examples:

1. Common Cards

In Magic, when you buy a new pack, 11 cards are "common", 3 are "uncommon" and one is "rare". Experienced players buy lots of cards and can have access to lots of rares, but new players generally just buy a few cards, so most of their cards are common. Therefore, the complexity of the cards at common determines how much complexity newcomers have to deal with.

2. Keywords

One way to reduce "effective complexity" is to bundle concepts together in a keyword. Instead of saying "this creature deals damage to each of the creatures blocking it and then deals the remainder of its damage to the player", it just says "Trample". There's an initial cost of learning what Trample means, but afterwards, every time you see the word "Trample" on a creature it works the same way.

Trample has some neat things going for it: it sounds evocative, and gets to build off of existing ideas in your brain. You already know what a big animal looks like. You can imagine a small creature getting in the way of the elephant, and it slowing the elephant down slightly but not really stopping it, and the elephant continuing on, trampling over it, and then going on to attack some bigger target.

This imagery is helpful for intuiting what the rules mean, even if the wording is somewhat confusing.

The problem comes when you introduce too many keywords at once. It gets overwhelming. Which brings to a final concept:

3. Evergreen keywords

Every 3 months, new magic cards are released to keep things fresh. New keywords are introduced (usually 3-5).

But there are some keywords (like Trample) that are *always* in season. There are about 16 evergreen keywords. Many of them are pretty intuitive (such as flying creatures only be able to be blocked by other flying creatures) so they aren't hard to learn.

A new player has an implicit goal of "learn all the evergreen keywords", which is a manageable task.

II. Building a high level conversation

I think some of this applies to the rationalsphere, where a lot of important concepts have been built up, or, combined together from neighboring disciplines. (See Anna Salmon's Single Conversational Locus)

Jargon is *useful*. They let you summarize a complex concept in a single word, and then have deeper conversations where each word packs a lot more meaning.

I have a lot of thoughts about how to do jargon *right*, which are beyond the scope of this post. But to summarize, I think good jargon:

encapusulates an idea that's important to build off of
lets you distinguish between *similar* concepts that have importantly-different-nuances. (viral infection vs bacterial infection)
provides some context clues that help you learn it (the way Trample does), while...
...not *also* resulting in people confusing what it means (a bad example perhaps being "negative reinforcement", which is not actually the same thing as "punishment")

Some considerations:

1) Sometimes you want a 101 space where you're either introducing ideas to a broader audience. Sometimes you want a 201 space where you're building on those ideas (either helping somewhat-less-newcomers build up a more advanced understanding, or literally developing new content at the cutting edge)

2) Different venues of conversation can have both different expectations of who-is-participating, and different social norms of what kind of participation is encouraged. (i.e an academic journal, a semi-formal internet forum, a facebook post)

3) Some concepts are pretty standalone: layfolk can learn them and use them immediately without having to fit them into a big edifice of theory

4) Furthermore, some concepts make good "gateway" terminology. They're useful standalone, but then they open up a world of ideas to you that you can then further explore.

So my thought is basically: if you are developing jargon, pay extra attention to whether this is Common or Expert Level jargon. There's not a clear dividing line between them, but roughly:

Common Jargon means you're expecting it to be a useful enough idea for layfolk to use regularly (or, you'd like to be able to have conversations with layfolk, or write popularization articles, that rely on the term already percolating into the mainstream, or, use it as a gateway term)

Consequently, it's much more important to put a lot of effort into choosing a term that:

resonates easily, is memorable...
...but avoids people latching onto the wrong aspect of it and misinterpreting it
doesn't sound like a weird insider term...
... but maybe ideally hints at a broader ecosystem of ideas

Expert Jargon is only really useful if you're buying into a broader ecosystem of ideas that build on each other. Accessibility and avoiding misunderstanding is still important if possible but being precise and build-on-able is more valuable.

Further Reading

This post was inspired by and builds upon:

Complexity is bad (Zvi Mowshowitz)
The Purple Sparkly Ball Thing (Malcolm Ocean)
New World Order (Mark Rosewater)